Suspicious Hidden Scheduled Task via TaskCache Security Descriptor Manipulation

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1053.005Scheduled Task
Persistence
- T1053.005Scheduled Task
- T1112Modify Registry
Priv Esc
- T1053.005Scheduled Task
Defense Evasion
- T1112Modify Registry
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects modification of the SD security-descriptor value under the scheduled-task TaskCache Tree registry hive, the technique used by the Tarrask malware attributed to Hafnium to hide a task so it does not appear in schtasks query output. Removing or altering the SD value conceals the persistence mechanism from defenders. This registry activity has no legitimate purpose and indicates deliberate task hiding.

Reporting behind it

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Suspicious Hidden Scheduled Task via TaskCache Security Descriptor Manipulation

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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