Suspicious Windows Defender or Firewall Service Disabled via Registry

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 registry modifications that disable Windows Defender or the Windows Firewall service mpssvc by setting their service Start value, a defense-evasion step observed after SolarWinds Web Help Desk exploitation. Turning off these services via the registry removes endpoint protection and network filtering before the actor deploys tooling. Direct edits to these security service keys outside patching windows are high-value indicators of tampering.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

Malicious Windows Defender Service Disable via Registry

Suspicious WMI Event Consumer Creation for MbRemoval Persistence via ps_script

Malicious Defender Exclusion Addition via Add-MpPreference

Suspicious Windows Defender Exclusion Added via Add-MpPreference

Malicious Defender Threat Action Override via Set-MpPreference

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Suspicious Chrome Update Suppression via simulate-outdated-no-au Flag via process_creation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

Malicious ELAM Driver Disable via Bcdedit

Suspicious Windows Defender or Firewall Service Disabled 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.

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