huntrule

Windows Registry UAC Bypass via winsat.exe LowerCaseLongPath and UACMe Path Parsing

Matches registry writes that reference winsat.exe using a LowerCaseLongPath construction consistent with UAC bypass path parsing.

FreeReviewedSigma · High · v1
Product
windows
Category
registry_set
Author
Christian Burkard (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2021-08-30
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

Priv Esc → Defense Evasion

  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Persistence

  6. Priv Esc

  7. Defense Evasion

  8. Cred Access

  9. Discovery

  10. Lateral Movement

  11. Collection

  12. C2

  13. Exfiltration

  14. Impact

What it detects

This rule flags registry entries where TargetObject indicates a winsat.exe path parsed through a LowerCaseLongPath component, matching a specific UAC bypass-style construction. Attackers may use this kind of path parsing abuse to trigger elevated behavior without direct authorization. The detection relies on registry_set telemetry capturing TargetObject and Details fields that contain the expected winsat.exe and temp path patterns.

Reporting behind it

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Windows Registry UAC Bypass via winsat.exe LowerCaseLongPath and UACMe Path Parsing
Pivot detection · T1548.002 · 9 related

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