Timestomping using Touch Commandedit

Timestomping is an anti-forensics technique which is used to modify the timestamps of a file, often to mimic files that are in the same folder.

Rule type: eql

Rule indices:

  • auditbeat-*
  • logs-endpoint.events.*

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
  • OS: macOS
  • Use Case: Threat Detection
  • Tactic: Defense Evasion
  • Data Source: Elastic Defend

Version: 106

Rule authors:

  • Elastic

Rule license: Elastic License v2

Setupedit

Setup

If enabling an EQL rule on a non-elastic-agent index (such as beats) for versions <8.2, events will not define event.ingested and default fallback for EQL rules was not added until version 8.2. Hence for this rule to work effectively, users will need to add a custom ingest pipeline to populate event.ingested to @timestamp. For more details on adding a custom ingest pipeline refer - https://www.elastic.co/guide/en/fleet/current/data-streams-pipeline-tutorial.html

Rule queryedit

process where event.type == "start" and
 process.name : "touch" and user.id != "0" and
 process.args : ("-r", "-t", "-a*","-m*") and
 not process.args : (
   "/usr/lib/go-*/bin/go", "/usr/lib/dracut/dracut-functions.sh", "/tmp/KSInstallAction.*/m/.patch/*"
) and not process.parent.name in ("pmlogger_daily", "pmlogger_janitor", "systemd")

Framework: MITRE ATT&CKTM