Malicious Defender Real-Time Monitoring Disable via Registry

PremiumReviewedSigma · High · v1
Product
windows
Category
registry_set
Author
HuntRule
Published
2026-05-19
Updated
2026-08-28

ATT&CK techniques

Persistence → Defense Evasion
  1. Recon

  2. Resource Dev

  3. Initial Access

  4. Execution

  5. Priv Esc

  6. Defense Evasion

  7. Cred Access

  8. Discovery

  9. Lateral Movement

  10. Collection

  11. C2

  12. Exfiltration

  13. Impact

What it detects

This rule detects the DisableRealtimeMonitoring registry value being enabled to turn off Microsoft Defender real-time scanning. This was observed during Cephalus ransomware deployment alongside service stops and exclusions. Disabling real-time monitoring removes on-access detection so the encryptor can run freely.

Related detections9 linkedT1685 — drag to rearrange
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Suspicious Remote Desktop Enabled via fDenyTSConnections Registry by Sandworm
Suspicious Windows Defender Real-Time Protection Disabled via Policy Registry by Cephalus Ransomware
Suspicious Microsoft Defender Path Exclusion of User Directories (via process_creation)
Malicious Windows Defender Tampering via Set-MpPreference (via process_creation)
Malicious Container Runtime Tampering via chmod on runc (via process_creation)
Malicious Gh0stBins RAT Registry Marker HHClient
Suspicious PebbleDash C2 Configuration Stored Under WMI Security Key (via registry_set)
Malicious Defender Real-Time Monitoring Disable via Registry
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.