Adversaries may disable or modify the Linux audit system to hide malicious activity and avoid detection. Linux admins use the Linux Audit system to track security-relevant information on a system. The Linux Audit system operates at the kernel-level and maintains event logs on application and system activity such as process, network, file, and login events based on pre-configured rules.
Often referred to as auditd, this is the name of the daemon used to write events to disk and is governed by the parameters set in the audit.conf configuration file. Two primary ways to configure the log generation rules are through the command line auditctl utility and the file /etc/audit/audit.rules, containing a sequence of auditctl commands loaded at boot time.(Citation: Red Hat System Auditing)(Citation: IzyKnows auditd threat detection 2022)
With root privileges, adversaries may be able to ensure their activity is not logged through disabling the Audit system service, editing the configuration/rule files, or by hooking the Audit system library functions. Using the command line, adversaries can disable the Audit system service through killing processes associated with auditd daemon or use systemctl to stop the Audit service. Adversaries can also hook Audit system functions to disable logging or modify the rules contained in the /etc/audit/audit.rules or audit.conf files to ignore malicious activity.(Citation: Trustwave Honeypot SkidMap 2023)(Citation: ESET Ebury Feb 2014)
| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| PR.AA-05.01 | Access privilege limitation | Mitigates | T1562.012 | Disable or Modify Linux Audit System |
Comments
This diagnostic statement describes the implementation of least privilege principle, which can be applied to limiting permissions through role-based access controls, file and directory permissions, and the execution of systems and services. An adversary must already have high-level, admin or root level access on a local system to make full use of these ATT&CK techniques. Restrict users and accounts to the least privileges they require can help mitigate these techniques.
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| PR.AA-01.01 | Identity and credential management | Mitigates | T1562.012 | Disable or Modify Linux Audit System |
Comments
This diagnostic statement protects against Disable or Modify Linux Audit System through the use of hardened access control policies, secure defaults, password complexity requirements, multifactor authentication requirements, and removal of terminated accounts.
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| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| CM-06 | Configuration Settings | mitigates | T1562.012 | Disable or Modify Linux Audit System | |
| CM-05 | Access Restrictions for Change | mitigates | T1562.012 | Disable or Modify Linux Audit System | |
| SI-07 | Software, Firmware, and Information Integrity | mitigates | T1562.012 | Disable or Modify Linux Audit System | |
| SI-04 | System Monitoring | mitigates | T1562.012 | Disable or Modify Linux Audit System | |
| AC-06 | Least Privilege | mitigates | T1562.012 | Disable or Modify Linux Audit System | |
| AC-03 | Access Enforcement | mitigates | T1562.012 | Disable or Modify Linux Audit System | |
| AC-02 | Account Management | mitigates | T1562.012 | Disable or Modify Linux Audit System | |
| CM-03 | Configuration Change Control | mitigates | T1562.012 | Disable or Modify Linux Audit System |
| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| action.hacking.variety.Disable controls | Disable or interfere with security controls | related-to | T1562.012 | Disable or Modify Linux Audit System | |
| action.malware.variety.Disable controls | Disable or interfere with security controls | related-to | T1562.012 | Disable or Modify Linux Audit System |
| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| alerts_for_linux_machines | Alerts for Linux Machines | technique_scores | T1562.012 | Disable or Modify Linux Audit System |
Comments
This control may alert on activity which disables auditd logging on Linux endpoints. The auditd package may not be the only logging system being utilized and this control may not alert on activity that disables other logging software.
References
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| Capability ID | Capability Description | Mapping Type | ATT&CK ID | ATT&CK Name | Notes |
|---|---|---|---|---|---|
| google_secops | Google Security Operations | technique_scores | T1562.012 | Disable or Modify Linux Audit System |
Comments
Google Security Operations is able to trigger alerts based off inovcation of utilities (like auditctl).
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