huntrule

Suspicious UAC Bypass via CMSTP INF Auto-Install

PremiumReviewedSigma · High · v1
Product
windows
Category
process_creation
Author
HuntRule
Published
2026-05-12
Updated
2026-08-28
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 detects execution of cmstp.exe with the auto-install switch pointing to an INF file, a technique used to bypass User Account Control and execute arbitrary commands at high integrity. The Sliver C2 framework and multiple threat actors abuse this living-off-the-land binary to elevate privileges while evading defenses. Detecting it early helps stop attacker privilege escalation before further post-exploitation activity.

Reporting behind it

Related detections9 linkedT1548.002 — drag to rearrange
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Malicious DBatLoader DLL Sideloading via easinvoker.exe Loading netutils.dll (via image_load)
Suspicious dllhost.exe Spawned with CLSID and Anomalous Parent (via process_creation)
Malicious ms-settings DelegateExecute UAC Bypass Registry Change
Malicious User Account Control Bypass via Auto-Elevating Binary Hijack (via process_creation)
Suspicious Mock Trusted Directory with Trailing Space (via process_creation)
Suspicious UAC Bypass via ComputerDefaults Auto-Elevated Binary (via process_creation)
Suspicious UAC Bypass via CMSTP INF Auto-Install
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.