File made Immutable by Chattredit
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 guideedit
Rule queryedit
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 mappingedit
Framework: MITRE ATT&CKTM
-
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 historyedit
- Version 100 (8.5.0 release)
-
- Formatting only