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Windows AMSI Disabled by Registry Value Modification (AmsiEnable)

Alerts when Windows Script Settings AmsiEnable is set to 0x00000000 to disable AMSI.

FreeReviewedSigma · High · v1
Product
windows
Category
registry_set
Author
Swachchhanda Shrawan Poudel (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2025-12-25
Updated
2026-07-30
AnalysisDetection

ATT&CK techniques

  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 Windows registry modifications that set the AmsiEnable value under the Script Settings path to DWORD 0x00000000. Disabling AMSI can reduce the ability of security products to scan script content and other dynamic content for malicious behavior. It relies on telemetry from registry set events that capture the targeted registry key path and the value details written by the process.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange
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Malicious Defender Disable And Executable Exclusion Via Registry
Malicious UAC Disable via EnableLUA Registry Modification (via registry_set)
Malicious AMSI and ETW Patching via PowerShell Script
Malicious PowMix AMSI Bypass via amsiInitFailed
Suspicious ThrottleStop Driver Abuse for Defense Evasion in Ransomware Attacks
Malicious Disabling of Microsoft Defender Real-Time Protection via SystemSettingsAdminFlows by DeadLock Ransomware
Suspicious Security Software Uninstallation via WMIC Product Call Uninstall (Chaos Ransomware)
Suspicious Security Product Uninstall via wmic product call uninstall
Windows AMSI Disabled by Registry Value Modification (AmsiEnable)
Pivot detection · T1685 · 9 related

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