Update v0.13.3

O365 Excessive Single Sign-On Logon Errors

Identifies accounts with a high number of single sign-on (SSO) logon errors. Excessive logon errors may indicate an attempt to brute force a password or single sign-on token.

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Windows Defender Exclusions Added via PowerShell

Identifies modifications to the Windows Defender configuration settings using PowerShell to add exclusions at the folder directory or process level.

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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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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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Web Application Suspicious Activity: POST Request Declined

A POST request to web application returned a 403 response, which indicates the web application declined to process the request because the action requested was not allowed

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Web Application Suspicious Activity: Unauthorized Method

A request to web application returned a 405 response which indicates the web application declined to process the request because the HTTP method is not allowed for the resource

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Web Application Suspicious Activity: No User Agent

A request to a web application server contained no identifying user agent string.

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Web Application Suspicious Activity: sqlmap User Agent

This is an example of how to detect an unwanted web client user agent. This search matches the user agent for sqlmap 1.3.11, which is a popular FOSS tool for testing web applications for SQL injection vulnerabilities.

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Spike in AWS Error Messages

A machine learning job detected a significant spike in the rate of a particular error in the CloudTrail messages. Spikes in error messages may accompany attempts at privilege escalation, lateral movement, or discovery.

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Rare AWS Error Code

A machine learning job detected an unusual error in a CloudTrail message. These can be byproducts of attempted or successful persistence, privilege escalation, defense evasion, discovery, lateral movement, or collection.

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Unusual City For an AWS Command

A machine learning job detected AWS command activity that, while not inherently suspicious or abnormal, is sourcing from a geolocation (city) that is unusual for the command. This can be the result of compromised credentials or keys being used by a threat actor in a different geography then the authorized user(s).

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Unusual Country For an AWS Command

A machine learning job detected AWS command activity that, while not inherently suspicious or abnormal, is sourcing from a geolocation (country) that is unusual for the command. This can be the result of compromised credentials or keys being used by a threat actor in a different geography then the authorized user(s).

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Unusual AWS Command for a User

A machine learning job detected an AWS API command that, while not inherently suspicious or abnormal, is being made by a user context that does not normally use the command. This can be the result of compromised credentials or keys as someone uses a valid account to persist, move laterally, or exfil data.

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Google Workspace MFA Enforcement Disabled

Detects when multi-factor authentication (MFA) enforcement is disabled for Google Workspace users. An adversary may disable MFA enforcement in order to weaken an organization’s security controls.

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Google Workspace Password Policy Modified

Detects when a Google Workspace password policy is modified. An adversary may attempt to modify a password policy in order to weaken an organization’s security controls.

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MFA Disabled for Google Workspace Organization

Detects when multi-factor authentication (MFA) is disabled for a Google Workspace organization. An adversary may attempt to modify a password policy in order to weaken an organization’s security controls.

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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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Default Cobalt Strike Team Server Certificate

This rule detects the use of the default Cobalt Strike Team Server TLS certificate. Cobalt Strike is software for Adversary Simulations and Red Team Operations which are security assessments that replicate the tactics and techniques of an advanced adversary in a network. Modifications to the Packetbeat configuration can be made to include MD5 and SHA256 hashing algorithms (the default is SHA1) - see the Reference section for additional information on module configuration.

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DNS Activity to the Internet

This rule detects when an internal network client sends DNS traffic directly to the Internet. This is atypical behavior for a managed network, and can be indicative of malware, exfiltration, command and control, or, simply, misconfiguration. This DNS activity also impacts your organization’s ability to provide enterprise monitoring and logging of DNS, and opens your network to a variety of abuses and malicious communications.

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Roshal Archive (RAR) or PowerShell File Downloaded from the Internet

Detects a Roshal Archive (RAR) file or PowerShell script downloaded from the internet by an internal host. Gaining initial access to a system and then downloading encoded or encrypted tools to move laterally is a common practice for adversaries as a way to protect their more valuable tools and TTPs. This may be atypical behavior for a managed network and can be indicative of malware, exfiltration, or command and control.

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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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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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IPSEC NAT Traversal Port Activity

This rule detects events that could be describing IPSEC NAT Traversal traffic. IPSEC is a VPN technology that allows one system to talk to another using encrypted tunnels. NAT Traversal enables these tunnels to communicate over the Internet where one of the sides is behind a NAT router gateway. This may be common on your network, but this technique is also used by threat actors to avoid detection.

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SMTP on Port 26/TCP

This rule detects events that may indicate use of SMTP on TCP port 26. This port is commonly used by several popular mail transfer agents to deconflict with the default SMTP port 25. This port has also been used by a malware family called BadPatch for command and control of Windows systems.

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RDP (Remote Desktop Protocol) from the Internet

This rule detects network events that may indicate the use of RDP traffic from the Internet. RDP is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector.

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Telnet Port Activity

This rule detects network events that may indicate the use of Telnet traffic. Telnet is commonly used by system administrators to remotely control older or embed ed systems using the command line shell. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector. As a plain-text protocol, it may also expose usernames and passwords to anyone capable of observing the traffic.

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VNC (Virtual Network Computing) from the Internet

This rule detects network events that may indicate the use of VNC traffic from the Internet. VNC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector.

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VNC (Virtual Network Computing) to the Internet

This rule detects network events that may indicate the use of VNC traffic to the Internet. VNC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector.

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RPC (Remote Procedure Call) from the Internet

This rule detects network events that may indicate the use of RPC traffic from the Internet. RPC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector.

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RPC (Remote Procedure Call) to the Internet

This rule detects network events that may indicate the use of RPC traffic to the Internet. RPC is commonly used by system administrators to remotely control a system for maintenance or to use shared resources. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector.

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SMB (Windows File Sharing) Activity to the Internet

This rule detects network events that may indicate the use of Windows file sharing (also called SMB or CIFS) traffic to the Internet. SMB is commonly used within networks to share files, printers, and other system resources amongst trusted systems. It should almost never be directly exposed to the Internet, as it is frequently targeted and exploited by threat actors as an initial access or back-door vector or for data exfiltration.

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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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External Alerts

Generates a detection alert for each external alert written to the configured indices. Enabling this rule allows you to immediately begin investigating external alerts in the app.

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Mshta Making Network Connections

Identifies Mshta.exe making outbound network connections. This may indicate adversarial activity as Mshta is often leveraged by adversaries to execute malicious scripts and evade detection.

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Unusual Child Processes of RunDLL32

Identifies child processes of unusual instances of RunDLL32 where the command line parameters were suspicious. Misuse of RunDLL32 could indicate malicious activity.

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Suspicious CertUtil Commands

Identifies suspicious commands being used with certutil.exe. CertUtil is a native Windows component which is part of Certificate Services. CertUtil is often abused by attackers to live off the land for stealthier command and control or data exfiltration.

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External IP Lookup fron Non-Browser Process

Identifies domains commonly used by adversaries for post-exploitation IP lookups. It is common for adversaries to test for Internet access and acquire their external IP address after they have gained access to a system. Among others, this has been observed in campaigns leveraging the information stealer, Trickbot.

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Execution of File Written or Modified by Microsoft Office

Identifies an executable created by a Microsoft Office application and subsequently executed. These processes are often launched via scripts inside documents or during exploitation of MS Office applications.

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Execution of File Written or Modified by PDF Reader

Identifies a suspicious file that was written by a PDF reader application and subsequently executed. These processes are often launched via exploitation of PDF applications.

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Unusual Print Spooler Child Process

Detects unusual Print Spooler service (spoolsv.exe) child processes. This may indicate an attempt to exploit privilege escalation vulnerabilities related to the Printing Service on Windows.

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