Sigma rule: Remove Immutable File Attribute - Auditd

A detection rule from the SigmaHQ repository, shown as its author published it. Dataset version ref-19ac9b0d3f68, updated 2022-11-26T00:00:00.000Z.

Rule

Title: Remove Immutable File Attribute - Auditd
Status: test
Level: medium
Author: Jakob Weinzettl, oscd.community
Date: 2019-09-23
Modified: 2022-11-26
File: rules/linux/auditd/execve/lnx_auditd_chattr_immutable_removal.yml
Commit: ccbb0369507f796db0b0ae6854c8a2be471b9d84

Detects removing immutable file attribute.

Log source

product: linux
service: auditd

Detection

selection:
    type: 'EXECVE'
    a0|contains: 'chattr'
    a1|contains: '-i'
condition: selection

False positives (as the rule lists them)

Administrator interacting with immutable files (e.g. for instance backups).

MITRE ATT&CK ids this rule names

T1222.002

References

https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1222.002/T1222.002.md

Read on 2026-11-03T00:58:21.399Z under licence sigma-drl-1.1@d5f4c36a from https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/auditd/execve/lnx_auditd_chattr_immutable_removal.yml

Sources and licences

SigmaHQ
"Remove Immutable File Attribute - Auditd" by Jakob Weinzettl, oscd.community (SigmaHQ). Rule: https://github.com/SigmaHQ/sigma/blob/ccbb0369507f796db0b0ae6854c8a2be471b9d84/rules/linux/auditd/execve/lnx_auditd_chattr_immutable_removal.yml.
Licensed under the Detection Rule License (DRL) 1.1: https://github.com/SigmaHQ/Detection-Rule-License
Detection Rule License (DRL) 1.1

Cite this page

Dragons Eye Ransomware Tracker, "Sigma rule: Remove Immutable File Attribute - Auditd",
entity page, dataset version ref-19ac9b0d3f68, updated 2022-11-26T00:00:00.000Z,
https://ransomware-tracker.com/detections/sigma/a5b977d6-8a81-4475-91b9-49dbfcd941f7 (accessed 2026-11-03).
Underlying source: SigmaHQ rule a5b977d6-8a81-4475-91b9-49dbfcd941f7, commit ccbb0369507f796db0b0ae6854c8a2be471b9d84.

Pages change. The dataset version identifies the data, but no archive of old versions is kept, so this citation cannot be replayed later.