huntrule

Windows Security Audit: Registry Handle Write Access Requested for Defender Exclusions

Alerts on registry access requests with write/append permissions to Windows Defender exclusions key paths.

FreeReviewedSigma · Medium · v2
Product
windows
Service
security
Author
@BarryShooshooga, Nasreddine Bencherchali (Nextron Systems) (SigmaHQ), DRL 1.1
Published
2019-10-26
Updated
2026-07-31
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 identifies Windows Security audit events where a process requests a handle and attempts access to the Windows Defender exclusions registry path. It matches handle request and access attempt events combined with registry object names under \Microsoft\Windows Defender\Exclusions\ and write-related access masks (WriteData and AppendData). Such activity can be used to modify Defender exclusion settings, weakening endpoint security. The detection relies on Security event telemetry for 4656 and 4663, including the requested access masks and the registry object name.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange
Suspicious Windows Defender Exclusion via Add-MpPreference (via process_creation)
Malicious Windows Defender Service Tampering via PowerShell (via process_creation)
Windows Defender Disabled via DisableAntiSpyware Registry Key
Suspicious Vulnerable Intel Ethernet Driver Load for BYOVD via SCATTERED SPIDER (via driver_load)
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
Windows Security Audit: Registry Handle Write Access Requested for Defender Exclusions
Pivot detection · T1685 · 9 related

Changelog

v2
  1. v2
    Candidate ingested via manual entry.2026-07-31
  2. v1
    No changelog recorded for this version.2026-07-30

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