Disable or Modify Linux Audit System Log

T1685.004

Sub-technique of T1685 Disable or Modify Tools.View on attack.mitre.org

About this technique

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.

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.

Detection rules4

Rules on DetectionCode tagged with T1685.004.

Sigma1

RuleLevelLog source
Audit Rules Deleted Via Auditctlhighlinux / process_creation

Splunk3

RuleTypeRiskData source
Linux Auditd Auditd Daemon AbortAnomalyNULLLinux Auditd Daemon Abort
Linux Auditd Auditd Daemon ShutdownAnomalyNULLLinux Auditd Daemon End
Linux Auditd Auditd Daemon StartAnomalyNULLLinux Auditd Daemon Start

Groups0

None recorded.

Software1

Campaigns0

None recorded.

Procedure examples1

Software1

Used byProcedure example
MalwareEbury

Ebury disables OpenSSH, system (`systemd`), and audit logs (`/sbin/auditd`) when the backdoor is active.

References3

  1. ESET Ebury Feb 2014 Open source
    M.Léveillé, M.. (2014, February 21). An In-depth Analysis of Linux/Ebury. Retrieved April 19, 2019.
  2. IzyKnows auditd threat detection 2022 Open source
    IzySec. (2022, January 26). Linux auditd for Threat Detection. Retrieved September 29, 2023.
  3. Red Hat Linux Disable or Mod Open source
    Red Hat. (n.d.). Retrieved April 15, 2026.

Data from MITRE ATT&CK® (Enterprise). ATT&CK® is a registered trademark of The MITRE Corporation.