File made Immutable by Chattr
editFile made Immutable by Chattr
editDetects 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
editRule query
editprocess 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
editFramework: 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 history
edit- Version 100 (8.5.0 release)
-
- Formatting only