Suspicious Cron Job Executing Binary From var tmp via Process Creation

ATT&CK techniques

Execution → Priv Esc

Recon
Resource Dev
Initial Access
Execution
- T1053.003Cron
Persistence
- T1053.003Cron
Priv Esc
- T1053.003Cron
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects a cron daemon spawning a process from the /var/tmp directory. The trojanized Free Download Manager installs an /etc/cron.d/collect job that runs /var/tmp/crond every ten minutes, using cron to persist and periodically launch its reverse-shell payload from a world-writable path.

Reporting behind it

Related detections9 linkedT1053.003 — drag to rearrange

Suspicious Cron Job Downloading and Executing Payload via GlobalProtect Exploitation

Suspicious Remote Script Download Piped to Shell via 8220 Gang Hadooken

Suspicious Linux Crontab Reboot Persistence to Hidden Sys Cache Binary (via process_creation)

Suspicious Cron Persistence Installing a Downloader via Command Line

Suspicious Cron Persistence File Creation in System Cron Directories (via file_event)

Suspicious Cron Persistence via etc cron.d tsar (via file_event)

Suspicious Cron Job Persistence Creation on Linux (via process_creation)

Suspicious Cron Persistence File Created in System Cron Directories

Linux eBPF Backdoor File Persistence via cron.d and sudoers.d (ebpfbackdoor)

Suspicious Cron Job Executing Binary From var tmp via Process Creation

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.

Full detection rule

Unlock this rule to view and copy it

The detection logic is included with a plan. Everything else — context, mappings and implementation details — stays free on this page.

Sign in for 3 free unlocks

Signing in gives you 3 unlocks to spend on any rule in the library. No card, and they do not expire.

Also included

Unlocked rules convert on this page — to Splunk SPL or Splunk — Raw Index SPL or Microsoft Sentinel KQL or Microsoft Sentinel ASIM ASIM KQL or Microsoft Defender XDR KQL or Elastic Security KQL or Elastic Security Lucene or Elastic Security ES|QL or CrowdStrike Falcon CQL or SentinelOne PowerQuery or Palo Alto Cortex XDR XQL or Carbon Black Cloud Platform Search or Carbon Black EDR Process Search or Google Security Operations UDM Search or IBM QRadar AQL or Sumo Logic Cloud SIEM Rules expression or Rapid7 InsightIDR LEQL or Graylog Search or OpenSearch Lucene or OpenSearch PPL PPL or Grafana Loki LogQL or SQLite SQL or Zircolite SQLite — with the log-source profile the engine picked, the field map it used, and everything it could not express. Converting a rule you have unlocked costs no further credit.

See it run on a free rule →Convert your own rule →