Cron Job Created or Changed by Previously Unknown Processedit

Linux cron jobs are scheduled tasks that can be leveraged by malicious actors for persistence, privilege escalation and command execution. By creating or modifying cron job configurations, attackers can execute malicious commands or scripts at predefined intervals, ensuring their continued presence and enabling unauthorized activities.

Rule type: new_terms

Rule indices:

  • 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: 100

References:

Tags:

  • Domain: Endpoint
  • OS: Linux
  • Use Case: Threat Detection
  • Tactic: Persistence
  • Tactic: Privilege Escalation
  • Tactic: Execution
  • Data Source: Elastic Endgame

Version: 2

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule queryedit

host.os.type : "linux" and event.action : ("change" or "file_modify_event" or "creation" or "file_create_event") and
file.path : (/etc/cron.allow or /etc/cron.deny or /etc/cron.d/* or /etc/cron.hourly/* or /etc/cron.daily/* or
/etc/cron.weekly/* or /etc/cron.monthly/* or /etc/crontab or /var/spool/cron/* or /usr/sbin/cron or /usr/sbin/anacron)
and not (process.name : ("dpkg" or "dockerd" or "rpm" or "snapd") or file.extension : "swp")

Framework: MITRE ATT&CKTM