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.*
- endgame-*
Severity: medium
Risk score: 47
Runs every: 5m
Searches indices from: now-9m (Date Math format, see also Additional look-back time)
Maximum alerts per execution: 33
References: None
Tags:
- Domain: Endpoint
- OS: Linux
- Use Case: Threat Detection
- Tactic: Defense Evasion
- Data Source: Elastic Endgame
Version: 105
Rule authors:
- Elastic
Rule license: Elastic License v2
Investigation guideedit
Rule queryedit
process where host.os.type == "linux" and 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", "/usr/local/uems_agent/bin/*")
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/
-
Sub-technique:
- Name: Linux and Mac File and Directory Permissions Modification
- ID: T1222.002
- Reference URL: https://attack.mitre.org/techniques/T1222/002/