Suspicious Cron Persistence Installing a Downloader via Command Line

PremiumReviewedSigma · Medium · v1
Category
process_creation
Author
HuntRule
Published
2026-07-08
Updated
2026-08-28

ATT&CK techniques

Execution → Priv Esc
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Defense Evasion

  7. Cred Access

  8. Discovery

  9. Lateral Movement

  10. Collection

  11. C2

  12. Exfiltration

  13. Impact

What it detects

This rule detects a crontab entry being registered that embeds a curl or wget download command, indicating a scheduled task that re-fetches attacker code on a recurring basis. The OpenClaw supply chain campaign uses cron jobs for command-and-control persistence on macOS and Linux hosts. Flagging this uncovers a recurring foothold that survives reboots and re-establishes contact with the attacker.

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Suspicious Cron Job Persistence Creation on Linux (via process_creation)
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Linux eBPF Backdoor File Persistence via cron.d and sudoers.d (ebpfbackdoor)
Suspicious Cron Persistence Installing a Downloader via Command Line
Pivot detection · T1053.003 · 9 related

Detection content is published as a reviewed draft. Tune thresholds and exclusions against your own telemetry before enabling this rule for alerting.