IMPORTANT: No additional bug fixes or documentation updates will be released for this version. For the latest information, see the current release documentation.

« File Permission Modification in Writable Directory Finder Sync Plugin Registered and Enabled »

› › ›

File made Immutable by Chattr

edit

File made Immutable by Chattr

edit

Detects a file being made immutable using the chattr binary. Making a file immutable means it cannot be deleted or renamed, no link can be created to this file, most of the file’s metadata can not be modified, and the file can not be opened in write mode. Threat actors will commonly utilize this to prevent tampering or modification of their malicious files or any system files they have modified for purposes of persistence (e.g .ssh, /etc/passwd, etc.).

Rule type: eql

Rule indices:

auditbeat-*
logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5 minutes

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 33

Tags:

Elastic
Host
Linux
Threat Detection
Defense Evasion

Version: 100 (version history)

Added (Elastic Stack release): 8.4.0

Last modified (Elastic Stack release): 8.5.0

Rule authors: Elastic

Rule license: Elastic License v2

Investigation guide

edit

Rule query

edit

process where event.type == "start" and user.name == "root" and
process.executable : "/usr/bin/chattr" and process.args : ("-*i*",
"+*i*") and not process.parent.executable: "/lib/systemd/systemd"

Threat mapping

edit

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Defense Evasion
- ID: TA0005
- Reference URL: https://attack.mitre.org/tactics/TA0005/
Technique:
- Name: File and Directory Permissions Modification
- ID: T1222
- Reference URL: https://attack.mitre.org/techniques/T1222/

Rule version history

edit

Version 100 (8.5.0 release)

Formatting only

« File Permission Modification in Writable Directory Finder Sync Plugin Registered and Enabled »