Malicious UAC Bypass via SilentCleanup Scheduled Task Trigger

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1053.005Scheduled Task
Persistence
- T1053.005Scheduled Task
Priv Esc
- T1053.005Scheduled Task
- T1548.002Bypass User Account Control
Defense Evasion
- T1548.002Bypass User Account Control
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects schtasks running the built-in SilentCleanup task, the trigger stage of the environment-variable UAC bypass used by NightshadeC2. After hijacking the windir variable the botnet forced SilentCleanup to run so its auto-elevated context executed the attacker payload. On-demand invocation of SilentCleanup via schtasks is a reliable indicator of this UAC bypass.

Reporting behind it

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Malicious UAC Bypass via SilentCleanup Scheduled Task Trigger

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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