Suspicious CronTab Creation or Modification

Identifies attempts to create or modify a crontab via a process that is not crontab (i.e python, osascript, etc.). This activity should not be highly prevalent and could indicate the use of cron as a persistence mechanism by a threat actor.

Rule type: eql

Rule indices:

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: 100

References:

Tags:

Elastic
Host
macOS
Threat Detection
Persistence

Version: 1

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

edit

file where event.type != "deletion" and process.name != null and
  file.path : "/private/var/at/tabs/*" and not process.executable == "/usr/bin/crontab"

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
Technique:
- Name: Scheduled Task/Job
- ID: T1053
- Reference URL: https://attack.mitre.org/techniques/T1053/
Sub-technique:
- Name: Cron
- ID: T1053.003
- Reference URL: https://attack.mitre.org/techniques/T1053/003/

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