Malicious SYSTEM Persistence via Scheduled Task Running rundll32 at Startup (via process_creation)

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1053.005Scheduled Task
Persistence
- T1053.005Scheduled Task
Priv Esc
- T1053.005Scheduled Task
Defense Evasion
- T1218.011Rundll32
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects schtasks creating a SYSTEM-context ONSTART task whose action is rundll32 executing an exported function from a DLL in a public writable directory, the persistence mechanism used in the Cobalt Strike SOCKS LockBit intrusion. Adversaries chain a boot-triggered scheduled task with a rundll32 DLL export to reload their loader as SYSTEM after reboot, so this combination is a strong persistence and defense-evasion signal.

Reporting behind it

Related detections9 linkedT1053.005 — drag to rearrange

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Suspicious Scheduled Task Running rundll32 DllRegisterServer Every Minute

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Suspicious Per-Minute SYSTEM Scheduled Task With Highest Privileges

Malicious SYSTEM Persistence via Scheduled Task Running rundll32 at Startup (via process_creation)

Pivot detection · T1053.005 · 9 related

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

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