Update v8.10.5

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This section lists all updates associated with version 8.10.5 of the Fleet integration Prebuilt Security Detection Rules.

Rule Description Status Version

Potential Data Exfiltration Activity to an Unusual ISO Code

A machine learning job has detected data exfiltration to a particular geo-location (by region name). Data transfers to geo-locations that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

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Potential Data Exfiltration Activity to an Unusual IP Address

A machine learning job has detected data exfiltration to a particular geo-location (by IP address). Data transfers to geo-locations that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

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Potential Data Exfiltration Activity to an Unusual Destination Port

A machine learning job has detected data exfiltration to a particular destination port. Data transfer patterns that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

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Potential Data Exfiltration Activity to an Unusual Region

A machine learning job has detected data exfiltration to a particular geo-location (by region name). Data transfers to geo-locations that are outside the normal traffic patterns of an organization could indicate exfiltration over command and control channels.

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Spike in Bytes Sent to an External Device

A machine learning job has detected high bytes of data written to an external device. In a typical operational setting, there is usually a predictable pattern or a certain range of data that is written to external devices. An unusually large amount of data being written is anomalous and can signal illicit data copying or transfer activities.

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Spike in Bytes Sent to an External Device via Airdrop

A machine learning job has detected high bytes of data written to an external device via Airdrop. In a typical operational setting, there is usually a predictable pattern or a certain range of data that is written to external devices. An unusually large amount of data being written is anomalous and can signal illicit data copying or transfer activities.

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Unusual Process Writing Data to an External Device

A machine learning job has detected a rare process writing data to an external device. Malicious actors often use benign-looking processes to mask their data exfiltration activities. The discovery of such a process that has no legitimate reason to write data to external devices can indicate exfiltration.

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Machine Learning Detected DGA activity using a known SUNBURST DNS domain

A supervised machine learning model has identified a DNS question name that used by the SUNBURST malware and is predicted to be the result of a Domain Generation Algorithm.

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Potential DGA Activity

A population analysis machine learning job detected potential DGA (domain generation algorithm) activity. Such activity is often used by malware command and control (C2) channels. This machine learning job looks for a source IP address making DNS requests that have an aggregate high probability of being DGA activity.

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Machine Learning Detected a DNS Request With a High DGA Probability Score

A supervised machine learning model has identified a DNS question name with a high probability of sourcing from a Domain Generation Algorithm (DGA), which could indicate command and control network activity.

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Machine Learning Detected a DNS Request Predicted to be a DGA Domain

A supervised machine learning model has identified a DNS question name that is predicted to be the result of a Domain Generation Algorithm (DGA), which could indicate command and control network activity.

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Unusual Process Spawned by a Host

A machine learning job has detected a suspicious Windows process. This process has been classified as suspicious in two ways. It was predicted to be suspicious by the ProblemChild supervised ML model, and it was found to be an unusual process, on a host that does not commonly manifest malicious activity. Such a process may be an instance of suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

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Unusual Process Spawned by a Parent Process

A machine learning job has detected a suspicious Windows process. This process has been classified as malicious in two ways. It was predicted to be malicious by the ProblemChild supervised ML model, and it was found to be an unusual child process name, for the parent process, by an unsupervised ML model. Such a process may be an instance of suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

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Unusual Process Spawned by a User

A machine learning job has detected a suspicious Windows process. This process has been classified as malicious in two ways. It was predicted to be malicious by the ProblemChild supervised ML model, and it was found to be suspicious given that its user context is unusual and does not commonly manifest malicious activity,by an unsupervised ML model. Such a process may be an instance of suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

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Machine Learning Detected a Suspicious Windows Event Predicted to be Malicious Activity

A supervised machine learning model (ProblemChild) has identified a suspicious Windows process event with high probability of it being malicious activity. Alternatively, the model’s blocklist identified the event as being malicious.

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Machine Learning Detected a Suspicious Windows Event with a High Malicious Probability Score

A supervised machine learning model (ProblemChild) has identified a suspicious Windows process event with high probability of it being malicious activity. Alternatively, the model’s blocklist identified the event as being malicious.

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Suspicious Windows Process Cluster Spawned by a Host

A machine learning job combination has detected a set of one or more suspicious Windows processes with unusually high scores for malicious probability. These process(es) have been classified as malicious in several ways. The process(es) were predicted to be malicious by the ProblemChild supervised ML model. If the anomaly contains a cluster of suspicious processes, each process has the same host name, and the aggregate score of the event cluster was calculated to be unusually high by an unsupervised ML model. Such a cluster often contains suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

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Suspicious Windows Process Cluster Spawned by a Parent Process

A machine learning job combination has detected a set of one or more suspicious Windows processes with unusually high scores for malicious probability. These process(es) have been classified as malicious in several ways. The process(es) were predicted to be malicious by the ProblemChild supervised ML model. If the anomaly contains a cluster of suspicious processes, each process has the same parent process name, and the aggregate score of the event cluster was calculated to be unusually high by an unsupervised ML model. Such a cluster often contains suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

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Suspicious Windows Process Cluster Spawned by a User

A machine learning job combination has detected a set of one or more suspicious Windows processes with unusually high scores for malicious probability. These process(es) have been classified as malicious in several ways. The process(es) were predicted to be malicious by the ProblemChild supervised ML model. If the anomaly contains a cluster of suspicious processes, each process has the same user name, and the aggregate score of the event cluster was calculated to be unusually high by an unsupervised ML model. Such a cluster often contains suspicious or malicious activity, possibly involving LOLbins, that may be resistant to detection using conventional search rules.

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Potential Network Scan Executed From Host

This threshold rule monitors for the rapid execution of unix utilities that are capable of conducting network scans. Adversaries may leverage built-in tools such as ping, netcat or socat to execute ping sweeps across the network while attempting to evade detection or due to the lack of network mapping tools available on the compromised host.

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Potential Upgrade of Non-interactive Shell

Identifies when a non-interactive terminal (tty) is being upgraded to a fully interactive shell. Attackers may upgrade a simple reverse shell to a fully interactive tty after obtaining initial access to a host, in order to obtain a more stable connection.

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Netcat Listener Established via rlwrap

Monitors for the execution of a netcat listener via rlwrap. rlwrap is a readline wrapper, a small utility that uses the GNU Readline library to allow the editing of keyboard input for any command. This utility can be used in conjunction with netcat to gain a more stable reverse shell.

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Potential Linux Hack Tool Launched

Monitors for the execution of different processes that might be used by attackers for malicious intent. An alert from this rule should be investigated further, as hack tools are commonly used by blue teamers and system administrators as well.

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Potential SSH-IT SSH Worm Downloaded

Identifies processes that are capable of downloading files with command line arguments containing URLs to SSH-IT’s autonomous SSH worm. This worm intercepts outgoing SSH connections every time a user uses ssh.

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Setcap setuid/setgid Capability Set

This rule monitors for the addition of the cap_setuid+ep or cap_setgid+ep capabilities via setcap. Setuid (Set User ID) and setgid (Set Group ID) are Unix-like OS features that enable processes to run with elevated privileges, based on the file owner or group. Threat actors can exploit these attributes to achieve persistence by creating malicious binaries, allowing them to maintain control over a compromised system with elevated permissions.

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Potential Privilege Escalation via Python cap_setuid

This detection rule monitors for the execution of a system command with setuid or setgid capabilities via Python, followed by a uid or gid change to the root user. This sequence of events may indicate successful privilege escalation. Setuid (Set User ID) and setgid (Set Group ID) are Unix-like OS features that enable processes to run with elevated privileges, based on the file owner or group. Threat actors can exploit these attributes to escalate privileges to the privileges that are set on the binary that is being executed.

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Potential Masquerading as Communication Apps

Identifies suspicious instances of communications apps, both unsigned and renamed ones, that can indicate an attempt to conceal malicious activity, bypass security features such as allowlists, or trick users into executing malware.

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Expired or Revoked Driver Loaded

Identifies an attempt to load a revoked or expired driver. Adversaries may bring outdated drivers with vulnerabilities to gain code execution in kernel mode or abuse revoked certificates to sign their drivers.

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Potential Non-Standard Port SSH connection

Identifies potentially malicious processes communicating via a port paring typically not associated with SSH. For example, SSH over port 2200 or port 2222 as opposed to the traditional port 22. Adversaries may make changes to the standard port a protocol uses to bypass filtering or muddle analysis/parsing of network data.

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5

Security Software Discovery via Grep

Identifies the use of the grep command to discover known third-party macOS and Linux security tools, such as Antivirus or Host Firewall details.

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106

Potential Reverse Shell Activity via Terminal

Identifies the execution of a shell process with suspicious arguments which may be indicative of reverse shell activity.

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106

Suspicious JAVA Child Process

Identifies suspicious child processes of the Java interpreter process. This may indicate an attempt to execute a malicious JAR file or an exploitation attempt via a JAVA specific vulnerability.

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205

Hosts File Modified

The hosts file on endpoints is used to control manual IP address to hostname resolutions. The hosts file is the first point of lookup for DNS hostname resolution so if adversaries can modify the endpoint hosts file, they can route traffic to malicious infrastructure. This rule detects modifications to the hosts file on Microsoft Windows, Linux (Ubuntu or RHEL) and macOS systems.

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106

Modification of Standard Authentication Module or Configuration

Adversaries may modify the standard authentication module for persistence via patching the normal authorization process or modifying the login configuration to allow unauthorized access or elevate privileges.

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204

Bash Shell Profile Modification

Both ~/.bash_profile and ~/.bashrc are files containing shell commands that are run when Bash is invoked. These files are executed in a user’s context, either interactively or non-interactively, when a user logs in so that their environment is set correctly. Adversaries may abuse this to establish persistence by executing malicious content triggered by a user’s shell.

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104

SSH Authorized Keys File Modification

The Secure Shell (SSH) authorized_keys file specifies which users are allowed to log into a server using public key authentication. Adversaries may modify it to maintain persistence on a victim host by adding their own public key(s).

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204

Sudoers File Modification

A sudoers file specifies the commands that users or groups can run and from which terminals. Adversaries can take advantage of these configurations to execute commands as other users or spawn processes with higher privileges.

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203

Network Activity Detected via cat

This rule monitors for the execution of the cat command, followed by a connection attempt by the same process. Cat is capable of transfering data via tcp/udp channels by redirecting its read output to a /dev/tcp or /dev/udp channel. This activity is highly suspicious, and should be investigated. Attackers may leverage this capability to transfer tools or files to another host in the network or exfiltrate data while attempting to evade detection in the process.

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Potential Protocol Tunneling via Chisel Client

This rule monitors for common command line flags leveraged by the Chisel client utility followed by a connection attempt. Chisel is a command-line utility used for creating and managing TCP and UDP tunnels, enabling port forwarding and secure communication between machines. Attackers can abuse the Chisel utility to establish covert communication channels, bypass network restrictions, and carry out malicious activities by creating tunnels that allow unauthorized access to internal systems.

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Potential Protocol Tunneling via Chisel Server

This rule monitors for common command line flags leveraged by the Chisel server utility followed by a received connection within a timespan of 1 minute. Chisel is a command-line utility used for creating and managing TCP and UDP tunnels, enabling port forwarding and secure communication between machines. Attackers can abuse the Chisel utility to establish covert communication channels, bypass network restrictions, and carry out malicious activities by creating tunnels that allow unauthorized access to internal systems.

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Suspicious Utility Launched via ProxyChains

This rule monitors for the execution of suspicious linux tools through ProxyChains. ProxyChains is a command-line tool that enables the routing of network connections through intermediary proxies, enhancing anonymity and enabling access to restricted resources. Attackers can exploit the ProxyChains utility to hide their true source IP address, evade detection, and perform malicious activities through a chain of proxy servers, potentially masking their identity and intentions.

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Potential Linux Tunneling and/or Port Forwarding

This rule monitors for a set of Linux utilities that can be used for tunneling and port forwarding. Attackers can leverage tunneling and port forwarding techniques to bypass network defenses, establish hidden communication channels, and gain unauthorized access to internal resources, facilitating data exfiltration, lateral movement, and remote control.

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2

Suspicious Network Activity to the Internet by Previously Unknown Executable

This rule monitors for network connectivity to the internet from a previously unknown executable located in a suspicious directory to a previously unknown destination ip. An alert from this rule can indicate the presence of potentially malicious activity, such as the execution of unauthorized or suspicious processes attempting to establish connections to unknown or suspicious destinations such as a command and control server. Detecting and investigating such behavior can help identify and mitigate potential security threats, protecting the system and its data from potential compromise.

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Potential Protocol Tunneling via EarthWorm

Identifies the execution of the EarthWorm tunneler. Adversaries may tunnel network communications to and from a victim system within a separate protocol to avoid detection and network filtering, or to enable access to otherwise unreachable systems.

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107

Sensitive Files Compression

Identifies the use of a compression utility to collect known files containing sensitive information, such as credentials and system configurations.

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206

Potential Linux Credential Dumping via Unshadow

Identifies the execution of the unshadow utility which is part of John the Ripper, a password-cracking tool on the host machine. Malicious actors can use the utility to retrieve the combined contents of the /etc/shadow and /etc/password files. Using the combined file generated from the utility, the malicious threat actors can use them as input for password-cracking utilities or prepare themselves for future operations by gathering credential information of the victim.

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5

Linux init (PID 1) Secret Dump via GDB

This rule monitors for the potential memory dump of the init process (PID 1) through gdb. Attackers may leverage memory dumping techniques to attempt secret extraction from privileged processes. Tools that display this behavior include "truffleproc" and "bash-memory-dump". This behavior should not happen by default, and should be investigated thoroughly.

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Potential Linux Local Account Brute Force Detected

Identifies multiple consecutive login attempts executed by one process targeting a local linux user account within a short time interval. Adversaries might brute force login attempts across different users with a default wordlist or a set of customly crafted passwords in an attempt to gain access to these accounts.

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Potential External Linux SSH Brute Force Detected

Identifies multiple external consecutive login failures targeting a user account from the same source address within a short time interval. Adversaries will often brute force login attempts across multiple users with a common or known password, in an attempt to gain access to these accounts.

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Potential Internal Linux SSH Brute Force Detected

Identifies multiple internal consecutive login failures targeting a user account from the same source address within a short time interval. Adversaries will often brute force login attempts across multiple users with a common or known password, in an attempt to gain access to these accounts.

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Potential Successful Linux FTP Brute Force Attack Detected

An FTP (file transfer protocol) brute force attack is a method where an attacker systematically tries different combinations of usernames and passwords to gain unauthorized access to an FTP server, and if successful, the impact can include unauthorized data access, manipulation, or theft, compromising the security and integrity of the server and potentially exposing sensitive information. This rule identifies multiple consecutive authentication failures targeting a specific user account from the same source address and within a short time interval, followed by a successful authentication.

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Potential Successful Linux RDP Brute Force Attack Detected

An RDP (Remote Desktop Protocol) brute force attack involves an attacker repeatedly attempting various username and password combinations to gain unauthorized access to a remote computer via RDP, and if successful, the potential impact can include unauthorized control over the compromised system, data theft, or the ability to launch further attacks within the network, jeopardizing the security and confidentiality of the targeted system and potentially compromising the entire network infrastructure. This rule identifies multiple consecutive authentication failures targeting a specific user account within a short time interval, followed by a successful authentication.

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Potential Successful SSH Brute Force Attack

Identifies multiple SSH login failures followed by a successful one from the same source address. Adversaries can attempt to login into multiple users with a common or known password to gain access to accounts.

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Potential Linux Credential Dumping via Proc Filesystem

Identifies the execution of the mimipenguin exploit script which is linux adaptation of Windows tool mimikatz. Mimipenguin exploit script is used to dump clear text passwords from a currently logged-in user. The tool exploits a known vulnerability CVE-2018-20781. Malicious actors can exploit the cleartext credentials in memory by dumping the process and extracting lines that have a high probability of containing cleartext passwords.

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Potential OpenSSH Backdoor Logging Activity

Identifies a Secure Shell (SSH) client or server process creating or writing to a known SSH backdoor log file. Adversaries may modify SSH related binaries for persistence or credential access via patching sensitive functions to enable unauthorized access or to log SSH credentials for exfiltration.

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107

Attempt to Disable IPTables or Firewall

Adversaries may attempt to disable the iptables or firewall service in an attempt to affect how a host is allowed to receive or send network traffic.

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Attempt to Disable Syslog Service

Adversaries may attempt to disable the syslog service in an attempt to an attempt to disrupt event logging and evade detection by security controls.

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107

Base16 or Base32 Encoding/Decoding Activity

Adversaries may encode/decode data in an attempt to evade detection by host- or network-based security controls.

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106

System Binary Copied and/or Moved to Suspicious Directory

This rule monitors for the copying or moving of a system binary to a suspicious directory. Adversaries may copy/move and rename system binaries to evade detection. Copying a system binary to a different location should not occur often, so if it does, the activity should be investigated.

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File made Immutable by Chattr

Detects a file being made immutable using the chattr binary. Making a file immutable means it cannot be deleted or renamed, no link can be created to this file, most of the file’s metadata can not be modified, and the file can not be opened in write mode. Threat actors will commonly utilize this to prevent tampering or modification of their malicious files or any system files they have modified for purposes of persistence (e.g .ssh, /etc/passwd, etc.).

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Potential Disabling of AppArmor

This rule monitors for potential attempts to disable AppArmor. AppArmor is a Linux security module that enforces fine-grained access control policies to restrict the actions and resources that specific applications and processes can access. Adversaries may disable security tools to avoid possible detection of their tools and activities.

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Potential Disabling of SELinux

Identifies potential attempts to disable Security-Enhanced Linux (SELinux), which is a Linux kernel security feature to support access control policies. Adversaries may disable security tools to avoid possible detection of their tools and activities.

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106

ESXI Timestomping using Touch Command

Identifies instances where the touch command is executed on a Linux system with the "-r" flag, which is used to modify the timestamp of a file based on another file’s timestamp. The rule targets specific VM-related paths, such as "/etc/vmware/", "/usr/lib/vmware/", or "/vmfs/*". These paths are associated with VMware virtualization software, and their presence in the touch command arguments may indicate that a threat actor is attempting to tamper with timestamps of VM-related files and configurations on the system.

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File Deletion via Shred

Malware or other files dropped or created on a system by an adversary may leave traces behind as to what was done within a network and how. Adversaries may remove these files over the course of an intrusion to keep their footprint low or remove them at the end as part of the post-intrusion cleanup process.

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File Permission Modification in Writable Directory

Identifies file permission modifications in common writable directories by a non-root user. Adversaries often drop files or payloads into a writable directory and change permissions prior to execution.

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206

Creation of Hidden Files and Directories via CommandLine

Users can mark specific files as hidden simply by putting a "." as the first character in the file or folder name. Adversaries can use this to their advantage to hide files and folders on the system for persistence and defense evasion. This rule looks for hidden files or folders in common writable directories.

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106

Creation of Hidden Shared Object File

Identifies the creation of a hidden shared object (.so) file. Users can mark specific files as hidden simply by putting a "." as the first character in the file or folder name. Adversaries can use this to their advantage to hide files and folders on the system for persistence and defense evasion.

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107

Kernel Module Removal

Kernel modules are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. This rule identifies attempts to remove a kernel module.

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106

System Log File Deletion

Identifies the deletion of sensitive Linux system logs. This may indicate an attempt to evade detection or destroy forensic evidence on a system.

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108

Potential Hidden Process via Mount Hidepid

Identifies the execution of mount process with hidepid parameter, which can make processes invisible to other users from the system. Adversaries using Linux kernel version 3.2+ (or RHEL/CentOS v6.5+ above) can hide the process from other users. When hidepid=2 option is executed to mount the /proc filesystem, only the root user can see all processes and the logged-in user can only see their own process. This provides a defense evasion mechanism for the adversaries to hide their process executions from all other commands such as ps, top, pgrep and more. With the Linux kernel hardening hidepid option all the user has to do is remount the /proc filesystem with the option, which can now be monitored and detected.

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4

Potential Defense Evasion via PRoot

Identifies the execution of the PRoot utility, an open-source tool for user-space implementation of chroot, mount --bind, and binfmt_misc. Adversaries can leverage an open-source tool PRoot to expand the scope of their operations to multiple Linux distributions and simplify their necessary efforts. In a normal threat scenario, the scope of an attack is limited by the varying configurations of each Linux distribution. With PRoot, it provides an attacker with a consistent operational environment across different Linux distributions, such as Ubuntu, Fedora, and Alpine. PRoot also provides emulation capabilities that allow for malware built on other architectures, such as ARM, to be run.The post-exploitation technique called bring your own filesystem (BYOF), can be used by the threat actors to execute malicious payload or elevate privileges or perform network scans or orchestrate another attack on the environment. Although PRoot was originally not developed with malicious intent it can be easily tuned to work for one.

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Suspicious Renaming of ESXI Files

Identifies instances where VMware-related files, such as those with extensions like ".vmdk", ".vmx", ".vmxf", ".vmsd", ".vmsn", ".vswp", ".vmss", ".nvram", and ".vmem", are renamed on a Linux system. The rule monitors for the "rename" event action associated with these file types, which could indicate malicious activity.

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Suspicious Renaming of ESXI index.html File

Identifies instances where the "index.html" file within the "/usr/lib/vmware/*" directory is renamed on a Linux system. The rule monitors for the "rename" event action associated with this specific file and path, which could indicate malicious activity.

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4

ESXI Discovery via Find

Identifies instances where the find command is started on a Linux system with arguments targeting specific VM-related paths, such as "/etc/vmware/", "/usr/lib/vmware/", or "/vmfs/*". These paths are associated with VMware virtualization software, and their presence in the find command arguments may indicate that a threat actor is attempting to search for, analyze, or manipulate VM-related files and configurations on the system.

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4

ESXI Discovery via Grep

Identifies instances where a process named grep, egrep, or pgrep is started on a Linux system with arguments related to virtual machine (VM) files, such as "vmdk", "vmx", "vmxf", "vmsd", "vmsn", "vswp", "vmss", "nvram", or "vmem". These file extensions are associated with VM-related file formats, and their presence in grep command arguments may indicate that a threat actor is attempting to search for, analyze, or manipulate VM files on the system.

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4

Enumeration of Kernel Modules

Loadable Kernel Modules (or LKMs) are pieces of code that can be loaded and unloaded into the kernel upon demand. They extend the functionality of the kernel without the need to reboot the system. This identifies attempts to enumerate information about a kernel module.

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206

Hping Process Activity

Hping ran on a Linux host. Hping is a FOSS command-line packet analyzer and has the ability to construct network packets for a wide variety of network security testing applications, including scanning and firewall auditing.

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106

Nping Process Activity

Nping ran on a Linux host. Nping is part of the Nmap tool suite and has the ability to construct raw packets for a wide variety of security testing applications, including denial of service testing.

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106

Potential Pspy Process Monitoring Detected

This rule leverages auditd to monitor for processes scanning different processes within the /proc directory using the openat syscall. This is a strong indication for the usage of the pspy utility. Attackers may leverage the pspy process monitoring utility to monitor system processes without requiring root permissions, in order to find potential privilege escalation vectors.

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3

Sudo Command Enumeration Detected

This rule monitors for the usage of the sudo -l command, which is used to list the allowed and forbidden commands for the invoking user. Attackers may execute this command to enumerate commands allowed to be executed with sudo permissions, potentially allowing to escalate privileges to root.

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3

SUID/SGUID Enumeration Detected

This rule monitors for the usage of the "find" command in conjunction with SUID and SGUID permission arguments. SUID (Set User ID) and SGID (Set Group ID) are special permissions in Linux that allow a program to execute with the privileges of the file owner or group, respectively, rather than the privileges of the user running the program. In case an attacker is able to enumerate and find a binary that is misconfigured, they might be able to leverage this misconfiguration to escalate privileges by exploiting vulnerabilities or built-in features in the privileged program.

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3

Unusual User Privilege Enumeration via id

This rule monitors for a sequence of 20 "id" command executions within 1 second by the same parent process. This behavior is unusual, and may be indicative of the execution of an enumeration script such as LinPEAS or LinEnum. These scripts leverage the "id" command to enumerate the privileges of all users present on the system.

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Virtual Machine Fingerprinting

An adversary may attempt to get detailed information about the operating system and hardware. This rule identifies common locations used to discover virtual machine hardware by a non-root user. This technique has been used by the Pupy RAT and other malware.

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106

Abnormal Process ID or Lock File Created

Identifies the creation of a Process ID (PID), lock or reboot file created in temporary file storage paradigm (tmpfs) directory /var/run. On Linux, the PID files typically hold the process ID to track previous copies running and manage other tasks. Certain Linux malware use the /var/run directory for holding data, executables and other tasks, disguising itself or these files as legitimate PID files.

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210

Potential curl CVE-2023-38545 Exploitation

Detects potential exploitation of curl CVE-2023-38545 by monitoring for vulnerable command line arguments in conjunction with an unusual command line length. A flaw in curl version ⇐ 8.3 makes curl vulnerable to a heap based buffer overflow during the SOCKS5 proxy handshake. Upgrade to curl version >= 8.4 to patch this vulnerability. This exploit can be executed with and without the use of environment variables. For increased visibility, enable the collection of http_proxy, HTTPS_PROXY and ALL_PROXY environment variables based on the instructions provided in the setup guide of this rule.

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2

File Creation, Execution and Self-Deletion in Suspicious Directory

This rule monitors for the creation of a file, followed by its execution and self-deletion in a short timespan within a directory often used for malicious purposes by threat actors. This behavior is often used by malware to execute malicious code and delete itself to hide its tracks.

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2

File Transfer or Listener Established via Netcat

A netcat process is engaging in network activity on a Linux host. Netcat is often used as a persistence mechanism by exporting a reverse shell or by serving a shell on a listening port. Netcat is also sometimes used for data exfiltration.

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108

Network Connection via Recently Compiled Executable

This rule monitors a sequence involving a program compilation event followed by its execution and a subsequent network connection event. This behavior can indicate the set up of a reverse tcp connection to a command-and-control server. Attackers may spawn reverse shells to establish persistence onto a target system.

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2

Interactive Terminal Spawned via Perl

Identifies when a terminal (tty) is spawned via Perl. Attackers may upgrade a simple reverse shell to a fully interactive tty after obtaining initial access to a host.

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106

Process Started from Process ID (PID) File

Identifies a new process starting from a process ID (PID), lock or reboot file within the temporary file storage paradigm (tmpfs) directory /var/run directory. On Linux, the PID files typically hold the process ID to track previous copies running and manage other tasks. Certain Linux malware use the /var/run directory for holding data, executables and other tasks, disguising itself or these files as legitimate PID files.

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107

Binary Executed from Shared Memory Directory

Identifies the execution of a binary by root in Linux shared memory directories: (/dev/shm/, /run/shm/, /var/run/, /var/lock/). This activity is to be considered highly abnormal and should be investigated. Threat actors have placed executables used for persistence on high-uptime servers in these directories as system backdoors.

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107

Interactive Terminal Spawned via Python

Identifies when a terminal (tty) is spawned via Python. Attackers may upgrade a simple reverse shell to a fully interactive tty after obtaining initial access to a host.

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108

Potential Code Execution via Postgresql

This rule monitors for suspicious activities that may indicate an attacker attempting to execute arbitrary code within a PostgreSQL environment. Attackers can execute code via PostgreSQL as a result of gaining unauthorized access to a public facing PostgreSQL database or exploiting vulnerabilities, such as remote command execution and SQL injection attacks, which can result in unauthorized access and malicious actions, and facilitate post-exploitation activities for unauthorized access and malicious actions.

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4

Linux Restricted Shell Breakout via Linux Binary(s)

Identifies the abuse of a Linux binary to break out of a restricted shell or environment by spawning an interactive system shell. The activity of spawning a shell from a binary is not common behavior for a user or system administrator, and may indicate an attempt to evade detection, increase capabilities or enhance the stability of an adversary.

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110

Deprecated - Potential Reverse Shell via Suspicious Parent Process

This detection rule detects the creation of a shell through a suspicious parent child relationship. Any reverse shells spawned by the specified utilities that use a forked process to initialize the connection attempt will be captured through this rule. Attackers may spawn reverse shells to establish persistence onto a target system.

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5

Potential Reverse Shell via Background Process

Monitors for the execution of background processes with process arguments capable of opening a socket in the /dev/tcp channel. This may indicate the creation of a backdoor reverse connection, and should be investigated further.

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2

Potential Reverse Shell via Java

This detection rule identifies the execution of a Linux shell process from a Java JAR application post an incoming network connection. This behavior may indicate reverse shell activity via a Java application.

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4

Potential Reverse Shell via Suspicious Child Process

This detection rule detects the creation of a shell through a suspicious process chain. Any reverse shells spawned by the specified utilities that are initialized from a single process followed by a network connection attempt will be captured through this rule. Attackers may spawn reverse shells to establish persistence onto a target system.

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5

Potential Meterpreter Reverse Shell

This detection rule identifies a sample of suspicious Linux system file reads used for system fingerprinting, leveraged by the Metasploit Meterpreter shell to gather information about the target that it is executing its shell on. Detecting this pattern is indicative of a successful meterpreter shell connection.

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2

Potential Reverse Shell via Suspicious Binary

This detection rule detects the creation of a shell through a chain consisting of the execution of a suspicious binary (located in a commonly abused location or executed manually) followed by a network event and ending with a shell being spawned. Stageless reverse tcp shells display this behaviour. Attackers may spawn reverse shells to establish persistence onto a target system.

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5

Potential Reverse Shell

This detection rule identifies suspicious network traffic patterns associated with TCP reverse shell activity. This activity consists of a parent-child relationship where a network event is followed by the creation of a shell process. An attacker may establish a Linux TCP reverse shell to gain remote access to a target system.

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5

Potential Reverse Shell via UDP

This detection rule identifies suspicious network traffic patterns associated with UDP reverse shell activity. This activity consists of a sample of an execve, socket and connect syscall executed by the same process, where the auditd.data.a0-1 indicate a UDP connection, ending with an egress connection event. An attacker may establish a Linux UDP reverse shell to bypass traditional firewall restrictions and gain remote access to a target system covertly.

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2

Suspicious Content Extracted or Decompressed via Funzip

Identifies when suspicious content is extracted from a file and subsequently decompressed using the funzip utility. Malware may execute the tail utility using the "-c" option to read a sequence of bytes from the end of a file. The output from tail can be piped to funzip in order to decompress malicious code before it is executed. This behavior is consistent with malware families such as Bundlore.

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3

Suspicious System Commands Executed by Previously Unknown Executable

This rule monitors for the execution of several commonly used system commands executed by a previously unknown executable located in commonly abused directories. An alert from this rule can indicate the presence of potentially malicious activity, such as the execution of unauthorized or suspicious processes attempting to run malicious code. Detecting and investigating such behavior can help identify and mitigate potential security threats, protecting the system and its data from potential compromise.

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103

Suspicious Mining Process Creation Event

Identifies service creation events of common mining services, possibly indicating the infection of a system with a cryptominer.

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4

BPF filter applied using TC

Detects when the tc (transmission control) binary is utilized to set a BPF (Berkeley Packet Filter) on a network interface. Tc is used to configure Traffic Control in the Linux kernel. It can shape, schedule, police and drop traffic. A threat actor can utilize tc to set a bpf filter on an interface for the purpose of manipulating the incoming traffic. This technique is not at all common and should indicate abnormal, suspicious or malicious activity.

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106

Suspicious Data Encryption via OpenSSL Utility

Identifies when the openssl command-line utility is used to encrypt multiple files on a host within a short time window. Adversaries may encrypt data on a single or multiple systems in order to disrupt the availability of their target’s data and may attempt to hold the organization’s data to ransom for the purposes of extortion.

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3

Suspicious Termination of ESXI Process

Identifies instances where VMware processes, such as "vmware-vmx" or "vmx," are terminated on a Linux system by a "kill" command. The rule monitors for the "end" event type, which signifies the termination of a process. The presence of a "kill" command as the parent process for terminating VMware processes may indicate that a threat actor is attempting to interfere with the virtualized environment on the targeted system.

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4

Suspicious File Changes Activity Detected

This rule identifies a sequence of 100 file extension rename events within a set of common file paths by the same process in a timespan of 1 second. Ransomware is a type of malware that encrypts a victim’s files or systems and demands payment (usually in cryptocurrency) in exchange for the decryption key. One important indicator of a ransomware attack is the mass encryption of the file system, after which a new file extension is added to the file.

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6

Potential Linux Ransomware Note Creation Detected

This rule identifies a sequence of a mass file encryption event in conjunction with the creation of a .txt file with a file name containing ransomware keywords executed by the same process in a 1 second timespan. Ransomware is a type of malware that encrypts a victim’s files or systems and demands payment (usually in cryptocurrency) in exchange for the decryption key. One important indicator of a ransomware attack is the mass encryption of the file system, after which a new file extension is added to the file.

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6

High Number of Process Terminations

This rule identifies a high number (10) of process terminations via pkill from the same host within a short time period.

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109

Connection to External Network via Telnet

Telnet provides a command line interface for communication with a remote device or server. This rule identifies Telnet network connections to publicly routable IP addresses.

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105

Connection to Internal Network via Telnet

Telnet provides a command line interface for communication with a remote device or server. This rule identifies Telnet network connections to non-publicly routable IP addresses.

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105

Chkconfig Service Add

Detects the use of the chkconfig binary to manually add a service for management by chkconfig. Threat actors may utilize this technique to maintain persistence on a system. When a new service is added, chkconfig ensures that the service has either a start or a kill entry in every runlevel and when the system is rebooted the service file added will run providing long-term persistence.

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107

Modification of OpenSSH Binaries

Adversaries may modify SSH related binaries for persistence or credential access by patching sensitive functions to enable unauthorized access or by logging SSH credentials for exfiltration.

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106

Cron Job Created or Changed by Previously Unknown Process

Linux cron jobs are scheduled tasks that can be leveraged by malicious actors for persistence, privilege escalation and command execution. By creating or modifying cron job configurations, attackers can execute malicious commands or scripts at predefined intervals, ensuring their continued presence and enabling unauthorized activities.

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5

Dynamic Linker Copy

Detects the copying of the Linux dynamic loader binary and subsequent file creation for the purpose of creating a backup copy. This technique was seen recently being utilized by Linux malware prior to patching the dynamic loader in order to inject and preload a malicious shared object file. This activity should never occur and if it does then it should be considered highly suspicious or malicious.

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105

Suspicious File Creation in /etc for Persistence

Detects the manual creation of files in specific etc directories, via user root, used by Linux malware to persist and elevate privileges on compromised systems. File creation in these directories should not be entirely common and could indicate a malicious binary or script installing persistence mechanisms for long term access.

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109

Potential Persistence Through init.d Detected

Files that are placed in the /etc/init.d/ directory in Unix can be used to start custom applications, services, scripts or commands during start-up. Init.d has been mostly replaced in favor of Systemd. However, the "systemd-sysv-generator" can convert init.d files to service unit files that run at boot. Adversaries may add or alter files located in the /etc/init.d/ directory to execute malicious code upon boot in order to gain persistence on the system.

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6

Kernel Module Load via insmod

Detects the use of the insmod binary to load a Linux kernel object file. Threat actors can use this binary, given they have root privileges, to load a rootkit on a system providing them with complete control and the ability to hide from security products. Manually loading a kernel module in this manner should not be at all common and can indicate suspcious or malicious behavior.

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106

Persistence via KDE AutoStart Script or Desktop File Modification

Identifies the creation or modification of a K Desktop Environment (KDE) AutoStart script or desktop file that will execute upon each user logon. Adversaries may abuse this method for persistence.

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107

Potential Linux Backdoor User Account Creation

Identifies the attempt to create a new backdoor user by setting the user’s UID to 0. Attackers may alter a user’s UID to 0 to establish persistence on a system.

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4

Potential Remote Code Execution via Web Server

Identifies suspicious commands executed via a web server, which may suggest a vulnerability and remote shell access. Attackers may exploit a vulnerability in a web application to execute commands via a web server, or place a backdoor file that can be abused to gain code execution as a mechanism for persistence.

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5

Linux User Added to Privileged Group

Identifies attempts to add a user to a privileged group. Attackers may add users to a privileged group in order to establish persistence on a system.

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4

Potential Persistence Through MOTD File Creation Detected

Message of the day (MOTD) is the message that is presented to the user when a user connects to a Linux server via SSH or a serial connection. Linux systems contain several default MOTD files located in the "/etc/update-motd.d/" and "/usr/lib/update-notifier/" directories. These scripts run as the root user every time a user connects over SSH or a serial connection. Adversaries may create malicious MOTD files that grant them persistence onto the target every time a user connects to the system by executing a backdoor script or command. This rule detects the creation of potentially malicious files within the default MOTD file directories.

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6

Suspicious Process Spawned from MOTD Detected

Message of the day (MOTD) is the message that is presented to the user when a user connects to a Linux server via SSH or a serial connection. Linux systems contain several default MOTD files located in the "/etc/update-motd.d/" and "/usr/lib/update-notifier/" directories. These scripts run as the root user every time a user connects over SSH or a serial connection. Adversaries may create malicious MOTD files that grant them persistence onto the target every time a user connects to the system by executing a backdoor script or command. This rule detects the execution of potentially malicious processes through the MOTD utility.

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6

Potential Persistence Through Run Control Detected

This rule monitors the creation/alteration of the rc.local file by a previously unknown process executable through the use of the new terms rule type. The /etc/rc.local file is used to start custom applications, services, scripts or commands during start-up. The rc.local file has mostly been replaced by Systemd. However, through the "systemd-rc-local-generator", rc.local files can be converted to services that run at boot. Adversaries may alter rc.local to execute malicious code at start-up, and gain persistence onto the system.

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107

Shared Object Created or Changed by Previously Unknown Process

This rule monitors the creation of shared object files by previously unknown processes. The creation of a shared object file involves compiling code into a dynamically linked library that can be loaded by other programs at runtime. While this process is typically used for legitimate purposes, malicious actors can leverage shared object files to execute unauthorized code, inject malicious functionality into legitimate processes, or bypass security controls. This allows malware to persist on the system, evade detection, and potentially compromise the integrity and confidentiality of the affected system and its data.

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4

New Systemd Timer Created

Detects the creation of a systemd timer within any of the default systemd timer directories. Systemd timers can be used by an attacker to gain persistence, by scheduling the execution of a command or script. Similarly to cron/at, systemd timers can be set up to execute on boot time, or on a specific point in time, which allows attackers to regain access in case the connection to the infected asset was lost.

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6

New Systemd Service Created by Previously Unknown Process

Systemd service files are configuration files in Linux systems used to define and manage system services. Malicious actors can leverage systemd service files to achieve persistence by creating or modifying service files to execute malicious commands or payloads during system startup. This allows them to maintain unauthorized access, execute additional malicious activities, or evade detection.

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5

Potential Unauthorized Access via Wildcard Injection Detected

This rule monitors for the execution of the "chown" and "chmod" commands with command line flags that could indicate a wildcard injection attack. Linux wildcard injection is a type of security vulnerability where attackers manipulate commands or input containing wildcards (e.g., *, ?, []) to execute unintended operations or access sensitive data by tricking the system into interpreting the wildcard characters in unexpected ways.

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3

Potential Privilege Escalation via Container Misconfiguration

This rule monitors for the execution of processes that interact with Linux containers through an interactive shell without root permissions. Utilities such as runc and ctr are universal command-line utilities leveraged to interact with containers via root permissions. On systems where the access to these utilities are misconfigured, attackers might be able to create and run a container that mounts the root folder or spawn a privileged container vulnerable to a container escape attack, which might allow them to escalate privileges and gain further access onto the host file system.

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3

Modification of Dynamic Linker Preload Shared Object

Identifies modification of the dynamic linker preload shared object (ld.so.preload). Adversaries may execute malicious payloads by hijacking the dynamic linker used to load libraries.

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207

Suspicious Symbolic Link Created

Identifies the creation of a symbolic link to a suspicious file or location. A symbolic link is a reference to a file or directory that acts as a pointer or shortcut, allowing users to access the target file or directory from a different location in the file system. An attacker can potentially leverage symbolic links for privilege escalation by tricking a privileged process into following the symbolic link to a sensitive file, giving the attacker access to data or capabilities they would not normally have.

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3

Potential Privilege Escalation via UID INT_MAX Bug Detected

This rule monitors for the execution of the systemd-run command by a user with a UID that is larger than the maximum allowed UID size (INT_MAX). Some older Linux versions were affected by a bug which allows user accounts with a UID greater than INT_MAX to escalate privileges by spawning a shell through systemd-run.

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3

Kernel Load or Unload via Kexec Detected

This detection rule identifies the usage of kexec, helping to uncover unauthorized kernel replacements and potential compromise of the system’s integrity. Kexec is a Linux feature that enables the loading and execution of a different kernel without going through the typical boot process. Malicious actors can abuse kexec to bypass security measures, escalate privileges, establish persistence or hide their activities by loading a malicious kernel, enabling them to tamper with the system’s trusted state, allowing e.g. a VM Escape.

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4

Potential Privilege Escalation via CVE-2023-4911

This rule detects potential privilege escalation attempts through Looney Tunables (CVE-2023-4911). Looney Tunables is a buffer overflow vulnerability in GNU C Library’s dynamic loader’s processing of the GLIBC_TUNABLES environment variable.

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2

Potential Privilege Escalation via OverlayFS

Identifies an attempt to exploit a local privilege escalation (CVE-2023-2640 and CVE-2023-32629) via a flaw in Ubuntu’s modifications to OverlayFS. These flaws allow the creation of specialized executables, which, upon execution, grant the ability to escalate privileges to root on the affected machine.

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3

Potential Privilege Escalation via PKEXEC

Identifies an attempt to exploit a local privilege escalation in polkit pkexec (CVE-2021-4034) via unsecure environment variable injection. Successful exploitation allows an unprivileged user to escalate to the root user.

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106

Potential Shell via Wildcard Injection Detected

This rule monitors for the execution of a set of linux binaries, that are potentially vulnerable to wildcard injection, with suspicious command line flags followed by a shell spawn event. Linux wildcard injection is a type of security vulnerability where attackers manipulate commands or input containing wildcards (e.g., *, ?, []) to execute unintended operations or access sensitive data by tricking the system into interpreting the wildcard characters in unexpected ways.

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3

Potential Suspicious DebugFS Root Device Access

This rule monitors for the usage of the built-in Linux DebugFS utility to access a disk device without root permissions. Linux users that are part of the "disk" group have sufficient privileges to access all data inside of the machine through DebugFS. Attackers may leverage DebugFS in conjunction with "disk" permissions to read sensitive files owned by root, such as the shadow file, root ssh private keys or other sensitive files that may allow them to further escalate privileges.

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3

Potential Shadow File Read via Command Line Utilities

Identifies access to the /etc/shadow file via the commandline using standard system utilities. After elevating privileges to root, threat actors may attempt to read or dump this file in order to gain valid credentials. They may utilize these to move laterally undetected and access additional resources.

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107

Potential Sudo Privilege Escalation via CVE-2019-14287

This rule monitors for the execution of a suspicious sudo command that is leveraged in CVE-2019-14287 to escalate privileges to root. Sudo does not verify the presence of the designated user ID and proceeds to execute using a user ID that can be chosen arbitrarily. By using the sudo privileges, the command "sudo -u#-1" translates to an ID of 0, representing the root user. This exploit may work for sudo versions prior to v1.28.

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2

Potential Sudo Hijacking Detected

Identifies the creation of a sudo binary located at /usr/bin/sudo. Attackers may hijack the default sudo binary and replace it with a custom binary or script that can read the user’s password in clear text to escalate privileges or enable persistence onto the system every time the sudo binary is executed.

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103

Potential Sudo Token Manipulation via Process Injection

This rule detects potential sudo token manipulation attacks through process injection by monitoring the use of a debugger (gdb) process followed by a successful uid change event during the execution of the sudo process. A sudo token manipulation attack is performed by injecting into a process that has a valid sudo token, which can then be used by attackers to activate their own sudo token. This attack requires ptrace to be enabled in conjunction with the existence of a living process that has a valid sudo token with the same uid as the current user.

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3

Potential Privilege Escalation via Recently Compiled Executable

This rule monitors a sequence involving a program compilation event followed by its execution and a subsequent alteration of UID permissions to root privileges. This behavior can potentially indicate the execution of a kernel or software privilege escalation exploit.

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2

Namespace Manipulation Using Unshare

Identifies suspicious usage of unshare to manipulate system namespaces. Unshare can be utilized to escalate privileges or escape container security boundaries. Threat actors have utilized this binary to allow themselves to escape to the host and access other resources or escalate privileges.

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7

Potential Privilege Escalation through Writable Docker Socket

This rule monitors for the usage of Docker runtime sockets to escalate privileges on Linux systems. Docker sockets by default are only be writable by the root user and docker group. Attackers that have permissions to write to these sockets may be able to create and run a container that allows them to escalate privileges and gain further access onto the host file system.

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3

Cobalt Strike Command and Control Beacon

Cobalt Strike is a threat emulation platform commonly modified and used by adversaries to conduct network attack and exploitation campaigns. This rule detects a network activity algorithm leveraged by Cobalt Strike implant beacons for command and control.

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105

Possible FIN7 DGA Command and Control Behavior

This rule detects a known command and control pattern in network events. The FIN7 threat group is known to use this command and control technique, while maintaining persistence in their target’s network.

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104

Halfbaked Command and Control Beacon

Halfbaked is a malware family used to establish persistence in a contested network. This rule detects a network activity algorithm leveraged by Halfbaked implant beacons for command and control.

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104

Potential Network Sweep Detected

This rule identifies a potential network sweep. A network sweep is a method used by attackers to scan a target network, identifying active hosts, open ports, and available services to gather information on vulnerabilities and weaknesses. This reconnaissance helps them plan subsequent attacks and exploit potential entry points for unauthorized access, data theft, or other malicious activities. This rule proposes threshold logic to check for connection attempts from one source host to 10 or more destination hosts on commonly used network services.

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4

Potential Network Scan Detected

This rule identifies a potential port scan. A port scan is a method utilized by attackers to systematically scan a target system or network for open ports, allowing them to identify available services and potential vulnerabilities. By mapping out the open ports, attackers can gather critical information to plan and execute targeted attacks, gaining unauthorized access, compromising security, and potentially leading to data breaches, unauthorized control, or further exploitation of the targeted system or network. This rule proposes threshold logic to check for connection attempts from one source host to 20 or more destination ports.

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4

Potential SYN-Based Network Scan Detected

This rule identifies a potential SYN-Based port scan. A SYN port scan is a technique employed by attackers to scan a target network for open ports by sending SYN packets to multiple ports and observing the response. Attackers use this method to identify potential entry points or services that may be vulnerable to exploitation, allowing them to launch targeted attacks or gain unauthorized access to the system or network, compromising its security and potentially leading to data breaches or further malicious activities. This rule proposes threshold logic to check for connection attempts from one source host to 10 or more destination ports using 2 or less packets per port.

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4

Inbound Connection to an Unsecure Elasticsearch Node

Identifies Elasticsearch nodes that do not have Transport Layer Security (TLS), and/or lack authentication, and are accepting inbound network connections over the default Elasticsearch port.

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104

Exporting Exchange Mailbox via PowerShell

Identifies the use of the Exchange PowerShell cmdlet, New-MailBoxExportRequest, to export the contents of a primary mailbox or archive to a .pst file. Adversaries may target user email to collect sensitive information.

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108

Exchange Mailbox Export via PowerShell

Identifies the use of the Exchange PowerShell cmdlet, New-MailBoxExportRequest, to export the contents of a primary mailbox or archive to a .pst file. Adversaries may target user email to collect sensitive information.

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6

PowerShell Suspicious Script with Audio Capture Capabilities

Detects PowerShell scripts that can record audio, a common feature in popular post-exploitation tooling.

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108

PowerShell Keylogging Script

Detects the use of Win32 API Functions that can be used to capture user keystrokes in PowerShell scripts. Attackers use this technique to capture user input, looking for credentials and/or other valuable data.

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110

Encrypting Files with WinRar or 7z

Identifies use of WinRar or 7z to create an encrypted files. Adversaries will often compress and encrypt data in preparation for exfiltration.

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108

Potential File Transfer via Certreq

Identifies Certreq making an HTTP Post request. Adversaries could abuse Certreq to download files or upload data to a remote URL.

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5

Connection to Commonly Abused Web Services

Adversaries may implement command and control (C2) communications that use common web services to hide their activity. This attack technique is typically targeted at an organization and uses web services common to the victim network, which allows the adversary to blend into legitimate traffic activity. These popular services are typically targeted since they have most likely been used before compromise, which helps malicious traffic blend in.

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108

Potential DNS Tunneling via NsLookup

This rule identifies a large number (15) of nslookup.exe executions with an explicit query type from the same host. This may indicate command and control activity utilizing the DNS protocol.

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107

Port Forwarding Rule Addition

Identifies the creation of a new port forwarding rule. An adversary may abuse this technique to bypass network segmentation restrictions.

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107

Potential Remote Desktop Tunneling Detected

Identifies potential use of an SSH utility to establish RDP over a reverse SSH Tunnel. This can be used by attackers to enable routing of network packets that would otherwise not reach their intended destination.

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107

Remote File Download via Script Interpreter

Identifies built-in Windows script interpreters (cscript.exe or wscript.exe) being used to download an executable file from a remote destination.

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108

Potential Credential Access via Windows Utilities

Identifies the execution of known Windows utilities often abused to dump LSASS memory or the Active Directory database (NTDS.dit) in preparation for credential access.

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109

NTDS or SAM Database File Copied

Identifies a copy operation of the Active Directory Domain Database (ntds.dit) or Security Account Manager (SAM) files. Those files contain sensitive information including hashed domain and/or local credentials.

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107

Potential Credential Access via Trusted Developer Utility

An instance of MSBuild, the Microsoft Build Engine, loaded DLLs (dynamically linked libraries) responsible for Windows credential management. This technique is sometimes used for credential dumping.

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108

FirstTime Seen Account Performing DCSync

This rule identifies when a User Account starts the Active Directory Replication Process for the first time. Attackers can use the DCSync technique to get credential information of individual accounts or the entire domain, thus compromising the entire domain.

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7

Potential Credential Access via DCSync

This rule identifies when a User Account starts the Active Directory Replication Process. Attackers can use the DCSync technique to get credential information of individual accounts or the entire domain, thus compromising the entire domain.

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110

Kerberos Pre-authentication Disabled for User

Identifies the modification of an account’s Kerberos pre-authentication options. An adversary with GenericWrite/GenericAll rights over the account can maliciously modify these settings to perform offline password cracking attacks such as AS-REP roasting.

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108

Access to a Sensitive LDAP Attribute

Identify access to sensitive Active Directory object attributes that contains credentials and decryption keys such as unixUserPassword, ms-PKI-AccountCredentials and msPKI-CredentialRoamingTokens.

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8

LSASS Process Access via Windows API

Identifies access attempts to the LSASS handle, which may indicate an attempt to dump credentials from LSASS memory.

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4

Potential Local NTLM Relay via HTTP

Identifies attempt to coerce a local NTLM authentication via HTTP using the Windows Printer Spooler service as a target. An adversary may use this primitive in combination with other techniques to elevate privileges on a compromised system.

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107

Sensitive Privilege SeEnableDelegationPrivilege assigned to a User

Identifies the assignment of the SeEnableDelegationPrivilege sensitive "user right" to a user. The SeEnableDelegationPrivilege "user right" enables computer and user accounts to be trusted for delegation. Attackers can abuse this right to compromise Active Directory accounts and elevate their privileges.

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108

Potential Credential Access via Renamed COM+ Services DLL

Identifies suspicious renamed COMSVCS.DLL Image Load, which exports the MiniDump function that can be used to dump a process memory. This may indicate an attempt to dump LSASS memory while bypassing command-line based detection in preparation for credential access.

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105

Potential Credential Access via LSASS Memory Dump

Identifies suspicious access to LSASS handle from a call trace pointing to DBGHelp.dll or DBGCore.dll, which both export the MiniDumpWriteDump method that can be used to dump LSASS memory content in preparation for credential access.

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207

Suspicious Remote Registry Access via SeBackupPrivilege

Identifies remote access to the registry using an account with Backup Operators group membership. This may indicate an attempt to exfiltrate credentials by dumping the Security Account Manager (SAM) registry hive in preparation for credential access and privileges elevation.

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108

Symbolic Link to Shadow Copy Created

Identifies the creation of symbolic links to a shadow copy. Symbolic links can be used to access files in the shadow copy, including sensitive files such as ntds.dit, System Boot Key and browser offline credentials.

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107

Adding Hidden File Attribute via Attrib

Adversaries can add the hidden attribute to files to hide them from the user in an attempt to evade detection.

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109

Modification of AmsiEnable Registry Key

Identifies modifications of the AmsiEnable registry key to 0, which disables the Antimalware Scan Interface (AMSI). An adversary can modify this key to disable AMSI protections.

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107

Clearing Windows Console History

Identifies when a user attempts to clear console history. An adversary may clear the command history of a compromised account to conceal the actions undertaken during an intrusion.

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107

Clearing Windows Event Logs

Identifies attempts to clear or disable Windows event log stores using Windows wevetutil command. This is often done by attackers in an attempt to evade detection or destroy forensic evidence on a system.

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108

Code Signing Policy Modification Through Registry

Identifies attempts to disable/modify the code signing policy through the registry. Code signing provides authenticity on a program, and grants the user with the ability to check whether the program has been tampered with. By allowing the execution of unsigned or self-signed code, threat actors can craft and execute malicious code.

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6

Windows Defender Disabled via Registry Modification

Identifies modifications to the Windows Defender registry settings to disable the service or set the service to be started manually.

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107

PowerShell Script Block Logging Disabled

Identifies attempts to disable PowerShell Script Block Logging via registry modification. Attackers may disable this logging to conceal their activities in the host and evade detection.

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107

Disabling Windows Defender Security Settings via PowerShell

Identifies use of the Set-MpPreference PowerShell command to disable or weaken certain Windows Defender settings.

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107

Disable Windows Event and Security Logs Using Built-in Tools

Identifies attempts to disable EventLog via the logman Windows utility, PowerShell, or auditpol. This is often done by attackers in an attempt to evade detection on a system.

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108

DNS-over-HTTPS Enabled via Registry

Identifies when a user enables DNS-over-HTTPS. This can be used to hide internet activity or the process of exfiltrating data. With this enabled, an organization will lose visibility into data such as query type, response, and originating IP, which are used to determine bad actors.

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106

Suspicious .NET Code Compilation

Identifies executions of .NET compilers with suspicious parent processes, which can indicate an attacker’s attempt to compile code after delivery in order to bypass security mechanisms.

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107

Microsoft Build Engine Started by a Script Process

An instance of MSBuild, the Microsoft Build Engine, was started by a script or the Windows command interpreter. This behavior is unusual and is sometimes used by malicious payloads.

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206

Microsoft Build Engine Using an Alternate Name

An instance of MSBuild, the Microsoft Build Engine, was started after being renamed. This is uncommon behavior and may indicate an attempt to run unnoticed or undetected.

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109

Microsoft Build Engine Started an Unusual Process

An instance of MSBuild, the Microsoft Build Engine, started a PowerShell script or the Visual C# Command Line Compiler. This technique is sometimes used to deploy a malicious payload using the Build Engine.

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207

Potential DLL Side-Loading via Trusted Microsoft Programs

Identifies an instance of a Windows trusted program that is known to be vulnerable to DLL Search Order Hijacking starting after being renamed or from a non-standard path. This is uncommon behavior and may indicate an attempt to evade defenses via side loading a malicious DLL within the memory space of one of those processes.

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107

Process Injection by the Microsoft Build Engine

An instance of MSBuild, the Microsoft Build Engine, created a thread in another process. This technique is sometimes used to evade detection or elevate privileges.

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105

Suspicious Endpoint Security Parent Process

A suspicious Endpoint Security parent process was detected. This may indicate a process hollowing or other form of code injection.

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107

Suspicious WerFault Child Process

A suspicious WerFault child process was detected, which may indicate an attempt to run via the SilentProcessExit registry key manipulation. Verify process details such as command line, network connections and file writes.

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108

Potential Windows Error Manager Masquerading

Identifies suspicious instances of the Windows Error Reporting process (WerFault.exe or Wermgr.exe) with matching command-line and process executable values performing outgoing network connections. This may be indicative of a masquerading attempt to evade suspicious child process behavior detections.

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106

Microsoft Windows Defender Tampering

Identifies when one or more features on Microsoft Defender are disabled. Adversaries may disable or tamper with Microsoft Defender features to evade detection and conceal malicious behavior.

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107

Network Connection via Signed Binary

Binaries signed with trusted digital certificates can execute on Windows systems protected by digital signature validation. Adversaries may use these binaries to live off the land and execute malicious files that could bypass application allowlists and signature validation.

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106

Unusual Network Activity from a Windows System Binary

Identifies network activity from unexpected system applications. This may indicate adversarial activity as these applications are often leveraged by adversaries to execute code and evade detection.

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108

Parent Process PID Spoofing

Identifies parent process spoofing used to thwart detection. Adversaries may spoof the parent process identifier (PPID) of a new process to evade process-monitoring defenses or to elevate privileges.

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105

Local Account TokenFilter Policy Disabled

Identifies registry modification to the LocalAccountTokenFilterPolicy policy. If this value exists (which doesn’t by default) and is set to 1, then remote connections from all local members of Administrators are granted full high-integrity tokens during negotiation.

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6

Suspicious .NET Reflection via PowerShell

Detects the use of Reflection.Assembly to load PEs and DLLs in memory in PowerShell scripts. Attackers use this method to load executables and DLLs without writing to the disk, bypassing security solutions.

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109

Potential Process Injection via PowerShell

Detects the use of Windows API functions that are commonly abused by malware and security tools to load malicious code or inject it into remote processes.

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108

Windows Firewall Disabled via PowerShell

Identifies when the Windows Firewall is disabled using PowerShell cmdlets, which can help attackers evade network constraints, like internet and network lateral communication restrictions.

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107

Process Termination followed by Deletion

Identifies a process termination event quickly followed by the deletion of its executable file. Malware tools and other non-native files dropped or created on a system by an adversary may leave traces to indicate to what occurred. Removal of these files can occur during an intrusion, or as part of a post-intrusion process to minimize the adversary’s footprint.

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107

Scheduled Tasks AT Command Enabled

Identifies attempts to enable the Windows scheduled tasks AT command via the registry. Attackers may use this method to move laterally or persist locally. The AT command has been deprecated since Windows 8 and Windows Server 2012, but still exists for backwards compatibility.

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106

Potential Secure File Deletion via SDelete Utility

Detects file name patterns generated by the use of Sysinternals SDelete utility to securely delete a file via multiple file overwrite and rename operations.

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107

SolarWinds Process Disabling Services via Registry

Identifies a SolarWinds binary modifying the start type of a service to be disabled. An adversary may abuse this technique to manipulate relevant security services.

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106

Suspicious Execution from a Mounted Device

Identifies when a script interpreter or signed binary is launched via a non-standard working directory. An attacker may use this technique to evade defenses.

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105

Suspicious Managed Code Hosting Process

Identifies a suspicious managed code hosting process which could indicate code injection or other form of suspicious code execution.

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105

Suspicious Process Access via Direct System Call

Identifies suspicious process access events from an unknown memory region. Endpoint security solutions usually hook userland Windows APIs in order to decide if the code that is being executed is malicious or not. It’s possible to bypass hooked functions by writing malicious functions that call syscalls directly.

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209

Suspicious Script Object Execution

Identifies scrobj.dll loaded into unusual Microsoft processes. This usually means a malicious scriptlet is being executed in the target process.

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105

Suspicious WMIC XSL Script Execution

Identifies WMIC allowlist bypass techniques by alerting on suspicious execution of scripts. When WMIC loads scripting libraries it may be indicative of an allowlist bypass.

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106

Suspicious Zoom Child Process

A suspicious Zoom child process was detected, which may indicate an attempt to run unnoticed. Verify process details such as command line, network connections, file writes and associated file signature details as well.

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108

Unusual Executable File Creation by a System Critical Process

Identifies an unexpected executable file being created or modified by a Windows system critical process, which may indicate activity related to remote code execution or other forms of exploitation.

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108

Unsigned DLL Side-Loading from a Suspicious Folder

Identifies a Windows trusted program running from locations often abused by adversaries to masquerade as a trusted program and loading a recently dropped DLL. This behavior may indicate an attempt to evade defenses via side-loading a malicious DLL within the memory space of a signed processes.

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5

Untrusted Driver Loaded

Identifies attempt to load an untrusted driver. Adversaries may modify code signing policies to enable execution of unsigned or self-signed code.

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6

AdFind Command Activity

This rule detects the Active Directory query tool, AdFind.exe. AdFind has legitimate purposes, but it is frequently leveraged by threat actors to perform post-exploitation Active Directory reconnaissance. The AdFind tool has been observed in Trickbot, Ryuk, Maze, and FIN6 campaigns. For Winlogbeat, this rule requires Sysmon.

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107

Account Discovery Command via SYSTEM Account

Identifies when the SYSTEM account uses an account discovery utility. This could be a sign of discovery activity after an adversary has achieved privilege escalation.

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107

PowerShell Share Enumeration Script

Detects scripts that contain PowerShell functions, structures, or Windows API functions related to windows share enumeration activities. Attackers, mainly ransomware groups, commonly identify and inspect network shares, looking for critical information for encryption and/or exfiltration.

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7

PowerShell Suspicious Discovery Related Windows API Functions

This rule detects the use of discovery-related Windows API functions in PowerShell Scripts. Attackers can use these functions to perform various situational awareness related activities, like enumerating users, shares, sessions, domain trusts, groups, etc.

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110

Command Execution via SolarWinds Process

A suspicious SolarWinds child process (Cmd.exe or Powershell.exe) was detected.

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107

Command Shell Activity Started via RunDLL32

Identifies command shell activity started via RunDLL32, which is commonly abused by attackers to host malicious code.

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107

Suspicious Portable Executable Encoded in Powershell Script

Detects the presence of a portable executable (PE) in a PowerShell script by looking for its encoded header. Attackers embed PEs into PowerShell scripts to inject them into memory, avoiding defences by not writing to disk.

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108

PsExec Network Connection

Identifies use of the SysInternals tool PsExec.exe making a network connection. This could be an indication of lateral movement.

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107

Network Connection via Registration Utility

Identifies the native Windows tools regsvr32.exe, regsvr64.exe, RegSvcs.exe, or RegAsm.exe making a network connection. This may be indicative of an attacker bypassing allowlists or running arbitrary scripts via a signed Microsoft binary.

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106

Outbound Scheduled Task Activity via PowerShell

Identifies the PowerShell process loading the Task Scheduler COM DLL followed by an outbound RPC network connection within a short time period. This may indicate lateral movement or remote discovery via scheduled tasks.

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105

Suspicious Cmd Execution via WMI

Identifies suspicious command execution (cmd) via Windows Management Instrumentation (WMI) on a remote host. This could be indicative of adversary lateral movement.

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107

Suspicious PDF Reader Child Process

Identifies suspicious child processes of PDF reader applications. These child processes are often launched via exploitation of PDF applications or social engineering.

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107

Suspicious Process Execution via Renamed PsExec Executable

Identifies suspicious psexec activity which is executing from the psexec service that has been renamed, possibly to evade detection.

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108

Conhost Spawned By Suspicious Parent Process

Detects when the Console Window Host (conhost.exe) process is spawned by a suspicious parent process, which could be indicative of code injection.

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107

Third-party Backup Files Deleted via Unexpected Process

Identifies the deletion of backup files, saved using third-party software, by a process outside of the backup suite. Adversaries may delete Backup files to ensure that recovery from a ransomware attack is less likely.

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108

Deleting Backup Catalogs with Wbadmin

Identifies use of the wbadmin.exe to delete the backup catalog. Ransomware and other malware may do this to prevent system recovery.

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107

Volume Shadow Copy Deletion via PowerShell

Identifies the use of the Win32_ShadowCopy class and related cmdlets to achieve shadow copy deletion. This commonly occurs in tandem with ransomware or other destructive attacks.

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107

Volume Shadow Copy Deletion via WMIC

Identifies use of wmic.exe for shadow copy deletion on endpoints. This commonly occurs in tandem with ransomware or other destructive attacks.

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107

Windows Script Executing PowerShell

Identifies a PowerShell process launched by either cscript.exe or wscript.exe. Observing Windows scripting processes executing a PowerShell script, may be indicative of malicious activity.

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107

Windows Script Interpreter Executing Process via WMI

Identifies use of the built-in Windows script interpreters (cscript.exe or wscript.exe) being used to execute a process via Windows Management Instrumentation (WMI). This may be indicative of malicious activity.

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107

Microsoft Exchange Server UM Writing Suspicious Files

Identifies suspicious files being written by the Microsoft Exchange Server Unified Messaging (UM) service. This activity has been observed exploiting CVE-2021-26858.

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105

Microsoft Exchange Server UM Spawning Suspicious Processes

Identifies suspicious processes being spawned by the Microsoft Exchange Server Unified Messaging (UM) service. This activity has been observed exploiting CVE-2021-26857.

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105

Microsoft Exchange Worker Spawning Suspicious Processes

Identifies suspicious processes being spawned by the Microsoft Exchange Server worker process (w3wp). This activity may indicate exploitation activity or access to an existing web shell backdoor.

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105

Suspicious MS Office Child Process

Identifies suspicious child processes of frequently targeted Microsoft Office applications (Word, PowerPoint, Excel). These child processes are often launched during exploitation of Office applications or from documents with malicious macros.

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108

Suspicious MS Outlook Child Process

Identifies suspicious child processes of Microsoft Outlook. These child processes are often associated with spear phishing activity.

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107

Suspicious Explorer Child Process

Identifies a suspicious Windows explorer child process. Explorer.exe can be abused to launch malicious scripts or executables from a trusted parent process.

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106

Incoming DCOM Lateral Movement with MMC

Identifies the use of Distributed Component Object Model (DCOM) to run commands from a remote host, which are launched via the MMC20 Application COM Object. This behavior may indicate an attacker abusing a DCOM application to move laterally.

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106

NullSessionPipe Registry Modification

Identifies NullSessionPipe registry modifications that specify which pipes can be accessed anonymously. This could be indicative of adversary lateral movement preparation by making the added pipe available to everyone.

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106

Potential Remote Desktop Shadowing Activity

Identifies the modification of the Remote Desktop Protocol (RDP) Shadow registry or the execution of processes indicative of an active RDP shadowing session. An adversary may abuse the RDP Shadowing feature to spy on or control other users active RDP sessions.

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106

Potential Lateral Tool Transfer via SMB Share

Identifies the creation or change of a Windows executable file over network shares. Adversaries may transfer tools or other files between systems in a compromised environment.

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107

Execution via TSClient Mountpoint

Identifies execution from the Remote Desktop Protocol (RDP) shared mountpoint tsclient on the target host. This may indicate a lateral movement attempt.

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106

Remote Execution via File Shares

Identifies the execution of a file that was created by the virtual system process. This may indicate lateral movement via network file shares.

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108

WMI Incoming Lateral Movement

Identifies processes executed via Windows Management Instrumentation (WMI) on a remote host. This could be indicative of adversary lateral movement, but could be noisy if administrators use WMI to remotely manage hosts.

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108

Incoming Execution via PowerShell Remoting

Identifies remote execution via Windows PowerShell remoting. Windows PowerShell remoting allows a user to run any Windows PowerShell command on one or more remote computers. This could be an indication of lateral movement.

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107

RDP Enabled via Registry

Identifies registry write modifications to enable Remote Desktop Protocol (RDP) access. This could be indicative of adversary lateral movement preparation.

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108

Suspicious RDP ActiveX Client Loaded

Identifies suspicious Image Loading of the Remote Desktop Services ActiveX Client (mstscax), this may indicate the presence of RDP lateral movement capability.

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105

Unusual Child Process of dns.exe

Identifies an unexpected process spawning from dns.exe, the process responsible for Windows DNS server services, which may indicate activity related to remote code execution or other forms of exploitation.

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107

Unusual File Modification by dns.exe

Identifies an unexpected file being modified by dns.exe, the process responsible for Windows DNS Server services, which may indicate activity related to remote code execution or other forms of exploitation.

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107

Lateral Movement via Startup Folder

Identifies suspicious file creations in the startup folder of a remote system. An adversary could abuse this to move laterally by dropping a malicious script or executable that will be executed after a reboot or user logon.

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105

AdminSDHolder Backdoor

Detects modifications in the AdminSDHolder object. Attackers can abuse the SDProp process to implement a persistent backdoor in Active Directory. SDProp compares the permissions on protected objects with those defined on the AdminSDHolder object. If the permissions on any of the protected accounts and groups do not match, the permissions on the protected accounts and groups are reset to match those of the domain’s AdminSDHolder object, regaining their Administrative Privileges.

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106

Adobe Hijack Persistence

Detects writing executable files that will be automatically launched by Adobe on launch.

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108

Registry Persistence via AppCert DLL

Detects attempts to maintain persistence by creating registry keys using AppCert DLLs. AppCert DLLs are loaded by every process using the common API functions to create processes.

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105

Registry Persistence via AppInit DLL

AppInit DLLs are dynamic-link libraries (DLLs) that are loaded into every process that creates a user interface (loads user32.dll) on Microsoft Windows operating systems. The AppInit DLL mechanism is used to load custom code into user-mode processes, allowing for the customization of the user interface and the behavior of Windows-based applications. Attackers who add those DLLs to the registry locations can execute code with elevated privileges, similar to process injection, and provide a solid and constant persistence on the machine.

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106

Image File Execution Options Injection

The Debugger and SilentProcessExit registry keys can allow an adversary to intercept the execution of files, causing a different process to be executed. This functionality can be abused by an adversary to establish persistence.

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105

Suspicious Startup Shell Folder Modification

Identifies suspicious startup shell folder modifications to change the default Startup directory in order to bypass detections monitoring file creation in the Windows Startup folder.

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108

Scheduled Task Created by a Windows Script

A scheduled task was created by a Windows script via cscript.exe, wscript.exe or powershell.exe. This can be abused by an adversary to establish persistence.

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105

Persistence via Microsoft Office AddIns

Detects attempts to establish persistence on an endpoint by abusing Microsoft Office add-ins.

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105

New ActiveSyncAllowedDeviceID Added via PowerShell

Identifies the use of the Exchange PowerShell cmdlet, Set-CASMailbox, to add a new ActiveSync allowed device. Adversaries may target user email to collect sensitive information.

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106

Persistence via PowerShell profile

Identifies the creation or modification of a PowerShell profile. PowerShell profile is a script that is executed when PowerShell starts to customize the user environment, which can be abused by attackers to persist in a environment where PowerShell is common.

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6

Account Password Reset Remotely

Identifies an attempt to reset a potentially privileged account password remotely. Adversaries may manipulate account passwords to maintain access or evade password duration policies and preserve compromised credentials.

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107

AdminSDHolder SDProp Exclusion Added

Identifies a modification on the dsHeuristics attribute on the bit that holds the configuration of groups excluded from the SDProp process. The SDProp compares the permissions on protected objects with those defined on the AdminSDHolder object. If the permissions on any of the protected accounts and groups do not match, the permissions on the protected accounts and groups are reset to match those of the domain’s AdminSDHolder object, meaning that groups excluded will remain unchanged. Attackers can abuse this misconfiguration to maintain long-term access to privileged accounts in these groups.

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108

Unsigned DLL Loaded by Svchost

Identifies an unsigned library created in the last 5 minutes and subsequently loaded by a shared windows service (svchost). Adversaries may use this technique to maintain persistence or run with System privileges.

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5

Unusual Persistence via Services Registry

Identifies processes modifying the services registry key directly, instead of through the expected Windows APIs. This could be an indication of an adversary attempting to stealthily persist through abnormal service creation or modification of an existing service.

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105

Startup Folder Persistence via Unsigned Process

Identifies files written or modified in the startup folder by unsigned processes. Adversaries may abuse this technique to maintain persistence in an environment.

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108

Component Object Model Hijacking

Identifies Component Object Model (COM) hijacking via registry modification. Adversaries may establish persistence by executing malicious content triggered by hijacked references to COM objects.

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108

Suspicious Image Load (taskschd.dll) from MS Office

Identifies a suspicious image load (taskschd.dll) from Microsoft Office processes. This behavior may indicate adversarial activity where a scheduled task is configured via Windows Component Object Model (COM). This technique can be used to configure persistence and evade monitoring by avoiding the usage of the traditional Windows binary (schtasks.exe) used to manage scheduled tasks.

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105

Suspicious Execution via Scheduled Task

Identifies execution of a suspicious program via scheduled tasks by looking at process lineage and command line usage.

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105

Suspicious ImagePath Service Creation

Identifies the creation of a suspicious ImagePath value. This could be an indication of an adversary attempting to stealthily persist or escalate privileges through abnormal service creation.

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105

System Shells via Services

Windows services typically run as SYSTEM and can be used as a privilege escalation opportunity. Malware or penetration testers may run a shell as a service to gain SYSTEM permissions.

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108

Temporarily Scheduled Task Creation

Indicates the creation and deletion of a scheduled task within a short time interval. Adversaries can use these to proxy malicious execution via the schedule service and perform clean up.

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7

Potential Persistence via Time Provider Modification

Identifies modification of the Time Provider. Adversaries may establish persistence by registering and enabling a malicious DLL as a time provider. Windows uses the time provider architecture to obtain accurate time stamps from other network devices or clients in the network. Time providers are implemented in the form of a DLL file which resides in the System32 folder. The service W32Time initiates during the startup of Windows and loads w32time.dll.

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105

Persistence via Hidden Run Key Detected

Identifies a persistence mechanism that utilizes the NtSetValueKey native API to create a hidden (null terminated) registry key. An adversary may use this method to hide from system utilities such as the Registry Editor (regedit).

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105

Installation of Security Support Provider

Identifies registry modifications related to the Windows Security Support Provider (SSP) configuration. Adversaries may abuse this to establish persistence in an environment.

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105

Persistence via TelemetryController Scheduled Task Hijack

Detects the successful hijack of Microsoft Compatibility Appraiser scheduled task to establish persistence with an integrity level of system.

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106

Persistence via Update Orchestrator Service Hijack

Identifies potential hijacking of the Microsoft Update Orchestrator Service to establish persistence with an integrity level of SYSTEM.

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108

Persistence via WMI Event Subscription

An adversary can use Windows Management Instrumentation (WMI) to install event filters, providers, consumers, and bindings that execute code when a defined event occurs. Adversaries may use the capabilities of WMI to subscribe to an event and execute arbitrary code when that event occurs, providing persistence on a system.

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107

Execution via MSSQL xp_cmdshell Stored Procedure

Identifies execution via MSSQL xp_cmdshell stored procedure. Malicious users may attempt to elevate their privileges by using xp_cmdshell, which is disabled by default, thus, it’s important to review the context of it’s use.

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107

Web Shell Detection: Script Process Child of Common Web Processes

Identifies suspicious commands executed via a web server, which may suggest a vulnerability and remote shell access.

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107

Modification of the msPKIAccountCredentials

Identify the modification of the msPKIAccountCredentials attribute in an Active Directory User Object. Attackers can abuse the credentials roaming feature to overwrite an arbitrary file for privilege escalation. ms-PKI-AccountCredentials contains binary large objects (BLOBs) of encrypted credential objects from the credential manager store, private keys, certificates, and certificate requests.

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7

Disabling User Account Control via Registry Modification

User Account Control (UAC) can help mitigate the impact of malware on Windows hosts. With UAC, apps and tasks always run in the security context of a non-administrator account, unless an administrator specifically authorizes administrator-level access to the system. This rule identifies registry value changes to bypass User Access Control (UAC) protection.

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107

First Time Seen Driver Loaded

Identifies the load of a driver with an original file name and signature values that were observed for the first time during the last 30 days. This rule type can help baseline drivers installation within your environment.

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6

Creation or Modification of a new GPO Scheduled Task or Service

Detects the creation or modification of a new Group Policy based scheduled task or service. These methods are used for legitimate system administration, but can also be abused by an attacker with domain admin permissions to execute a malicious payload remotely on all or a subset of the domain joined machines.

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106

Scheduled Task Execution at Scale via GPO

Detects the modification of Group Policy Object attributes to execute a scheduled task in the objects controlled by the GPO.

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108

Potential Privilege Escalation via InstallerFileTakeOver

Identifies a potential exploitation of InstallerTakeOver (CVE-2021-41379) default PoC execution. Successful exploitation allows an unprivileged user to escalate privileges to SYSTEM.

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108

Suspicious DLL Loaded for Persistence or Privilege Escalation

Identifies the loading of a non Microsoft signed DLL that is missing on a default Windows install (phantom DLL) or one that can be loaded from a different location by a native Windows process. This may be abused to persist or elevate privileges via privileged file write vulnerabilities.

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108

Potential Port Monitor or Print Processor Registration Abuse

Identifies port monitor and print processor registry modifications. Adversaries may abuse port monitor and print processors to run malicious DLLs during system boot that will be executed as SYSTEM for privilege escalation and/or persistence, if permissions allow writing a fully-qualified pathname for that DLL.

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105

Potential Privileged Escalation via SamAccountName Spoofing

Identifies a suspicious computer account name rename event, which may indicate an attempt to exploit CVE-2021-42278 to elevate privileges from a standard domain user to a user with domain admin privileges. CVE-2021-42278 is a security vulnerability that allows potential attackers to impersonate a domain controller via samAccountName attribute spoofing.

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106

Service Control Spawned via Script Interpreter

Identifies Service Control (sc.exe) spawning from script interpreter processes to create, modify, or start services. This can potentially indicate an attempt to elevate privileges or maintain persistence.

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107

UAC Bypass Attempt with IEditionUpgradeManager Elevated COM Interface

Identifies attempts to bypass User Account Control (UAC) by abusing an elevated COM Interface to launch a rogue Windows ClipUp program. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

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106

UAC Bypass Attempt via Elevated COM Internet Explorer Add-On Installer

Identifies User Account Control (UAC) bypass attempts by abusing an elevated COM Interface to launch a malicious program. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

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106

UAC Bypass via ICMLuaUtil Elevated COM Interface

Identifies User Account Control (UAC) bypass attempts via the ICMLuaUtil Elevated COM interface. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

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106

UAC Bypass via DiskCleanup Scheduled Task Hijack

Identifies User Account Control (UAC) bypass via hijacking DiskCleanup Scheduled Task. Attackers bypass UAC to stealthily execute code with elevated permissions.

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105

UAC Bypass Attempt via Privileged IFileOperation COM Interface

Identifies attempts to bypass User Account Control (UAC) via DLL side-loading. Attackers may attempt to bypass UAC to stealthily execute code with elevated permissions.

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106

Bypass UAC via Event Viewer

Identifies User Account Control (UAC) bypass via eventvwr.exe. Attackers bypass UAC to stealthily execute code with elevated permissions.

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108

UAC Bypass Attempt via Windows Directory Masquerading

Identifies an attempt to bypass User Account Control (UAC) by masquerading as a Microsoft trusted Windows directory. Attackers may bypass UAC to stealthily execute code with elevated permissions.

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108

UAC Bypass via Windows Firewall Snap-In Hijack

Identifies attempts to bypass User Account Control (UAC) by hijacking the Microsoft Management Console (MMC) Windows Firewall snap-in. Attackers bypass UAC to stealthily execute code with elevated permissions.

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108

Unusual Service Host Child Process - Childless Service

Identifies unusual child processes of Service Host (svchost.exe) that traditionally do not spawn any child processes. This may indicate a code injection or an equivalent form of exploitation.

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106