Sigma Rule Library

Linux Logs Clearing Attempts

Detects logs clearing attempts on Linux systems via utilities such as 'rm', 'rmdir', 'shred', and 'unlink' targeting log files and directories. Adversaries often try to clear logs to cover their tracks after performing malicious activities.

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Detection logic

selection

Image|endswith:
  - /rm
  - /rmdir
  - /shred
  - /unlink
CommandLine|contains:
  - /var/log
  - /var/spool/mail

filter_main_legit_systat

Image|endswith: /rm
CommandLine|startswith: rm -f /var/log/sysstat/

filter_main_dmseg

Image|endswith: /rm
CommandLine|startswith: rm -f -- /var/log//dmesg

Condition

selection and not 1 of filter_main_*

Raw YAML

title: Linux Logs Clearing Attempts
id: 80915f59-9b56-4616-9de0-fd0dea6c12fe
status: stable
description: |
    Detects logs clearing attempts on Linux systems via utilities such as 'rm', 'rmdir', 'shred', and 'unlink' targeting log files and directories.
    Adversaries often try to clear logs to cover their tracks after performing malicious activities.
references:
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.002/T1070.002.md
author: Ömer Günal, oscd.community
date: 2020-10-07
modified: 2026-03-18
tags:
    - attack.defense-impairment
    - attack.t1685.006
logsource:
    product: linux
    category: process_creation
detection:
    selection:
        Image|endswith:
            - '/rm'    # covers /rmdir as well
            - '/rmdir'
            - '/shred'
            - '/unlink'
        CommandLine|contains:
            - '/var/log'
            - '/var/spool/mail'
    filter_main_legit_systat:
        Image|endswith: '/rm'
        CommandLine|startswith: 'rm -f /var/log/sysstat/'
    filter_main_dmseg:
        Image|endswith: '/rm'
        CommandLine|startswith: 'rm -f -- /var/log//dmesg' # // before dmesg is not typo
    condition: selection and not 1 of filter_main_*
falsepositives:
    - Legitimate administration activities
level: medium

False positives

  • Legitimate administration activities

References

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