Linux process attempts to delete log files using rm, rmdir, shred, or unlink

Flags Linux attempts to remove or destroy log files via rm/rmdir/shred/unlink when /var/log or mail spool paths are referenced.

FreeReviewedSigma · Medium · v3
Product
linux
Category
process_creation
Author
Ömer Günal, oscd.community (SigmaHQ), DRL 1.1
Published
2020-10-07
Updated
2026-07-31
title: Linux process attempts to delete log files using rm, rmdir, shred, or unlink
id: 0617044c-186e-467e-9f1a-ad5df9f1591b
status: stable
description: This rule flags Linux process executions where the binary name ends with rm, rmdir, shred, or unlink and the command line includes references to /var/log or /var/spool/mail. Clearing or destroying logs can help attackers reduce forensic evidence after malicious activity. It relies on process creation telemetry (process image path and command line content) to identify likely log-targeting delete operations, while excluding a couple of specific rm -f sysstat and dmesg paths.
references:
  - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1070.002/T1070.002.md
  - https://github.com/SigmaHQ/sigma/blob/master/rules/linux/process_creation/proc_creation_lnx_clear_logs.yml
author: Ömer Günal, oscd.community, Huntrule Team
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
      - /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_*
falsepositives:
  - Legitimate administration activities
level: medium
license: DRL-1.1
related:
  - id: 80915f59-9b56-4616-9de0-fd0dea6c12fe
    type: derived