Suspicious Windows Defender Service Disabled via Registry (via registry_set)

ATT&CK techniques

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
Defense Evasion
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects BlotchyQuasar setting the WinDefend service start value to disabled in the registry to turn off Microsoft Defender at boot. Direct modification of the WinDefend service start type to disabled is a strong tampering signal. This persistently removes antivirus protection.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

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Malicious Defender Tampering via UnDefend Aggressive Flag

Suspicious Chrome Update Suppression via simulate-outdated-no-au Flag via process_creation

Suspicious Windows Defender Exclusion Added for Entire Windows Directory

Suspicious Windows Defender Service Disabled via Registry (via registry_set)

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.

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