Suspicious Symbolic Link Created
editSuspicious Symbolic Link Created
editIdentifies 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.
Rule type: eql
Rule indices:
- logs-endpoint.events.*
- endgame-*
Severity: low
Risk score: 21
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time
)
Maximum alerts per execution: 100
References: None
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Privilege Escalation
- Tactic: Credential Access
- Data Source: Elastic Endgame
- Data Source: Elastic Defend
Version: 4
Rule authors:
- Elastic
Rule license: Elastic License v2
Rule query
editprocess where host.os.type == "linux" and event.action in ("exec", "exec_event") and event.type == "start" and process.name == "ln" and process.args in ("-s", "-sf") and ( /* suspicious files */ (process.args in ("/etc/shadow", "/etc/shadow-", "/etc/shadow~", "/etc/gshadow", "/etc/gshadow-") or (process.working_directory == "/etc" and process.args in ("shadow", "shadow-", "shadow~", "gshadow", "gshadow-"))) or /* suspicious bins */ (process.args in ("/bin/bash", "/bin/dash", "/bin/sh", "/bin/tcsh", "/bin/csh", "/bin/zsh", "/bin/ksh", "/bin/fish") or (process.working_directory == "/bin" and process.args : ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish"))) or (process.args in ("/usr/bin/bash", "/usr/bin/dash", "/usr/bin/sh", "/usr/bin/tcsh", "/usr/bin/csh", "/usr/bin/zsh", "/usr/bin/ksh", "/usr/bin/fish") or (process.working_directory == "/usr/bin" and process.args in ("bash", "dash", "sh", "tcsh", "csh", "zsh", "ksh", "fish"))) or /* suspicious locations */ (process.args : ("/etc/cron.d/*", "/etc/cron.daily/*", "/etc/cron.hourly/*", "/etc/cron.weekly/*", "/etc/cron.monthly/*")) or (process.args : ("/home/*/.ssh/*", "/root/.ssh/*","/etc/sudoers.d/*", "/dev/shm/*")) ) and process.parent.name in ("bash", "dash", "ash", "sh", "tcsh", "csh", "zsh", "ksh", "fish") and not user.Ext.real.id == "0" and not group.Ext.real.id == "0"
Framework: MITRE ATT&CKTM
-
Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
-
Technique:
- Name: Abuse Elevation Control Mechanism
- ID: T1548
- Reference URL: https://attack.mitre.org/techniques/T1548/
-
Tactic:
- Name: Credential Access
- ID: TA0006
- Reference URL: https://attack.mitre.org/tactics/TA0006/
-
Technique:
- Name: OS Credential Dumping
- ID: T1003
- Reference URL: https://attack.mitre.org/techniques/T1003/
-
Sub-technique:
- Name: /etc/passwd and /etc/shadow
- ID: T1003.008
- Reference URL: https://attack.mitre.org/techniques/T1003/008/