Suspicious Windows Defender Real-Time Protection Disabled via Policy Registry by Cephalus Ransomware

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 changes under the Windows Defender Real-Time Protection policy key that disable on-access and real-time scanning, a defense evasion step used by Cephalus ransomware. Turning off these protections lets the encryptor run without interference.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

Malicious Microsoft Defender Real-Time Monitoring Disabled via Set-MpPreference (via process_creation)

Suspicious Windows Defender Exclusion Added via PowerShell via Process Creation (via process_creation)

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Suspicious ESXi Management Agent Stop via vpxa init Script (via process_creation)

Malicious ESXi Firewall Disable via esxcli (via process_creation)

Malicious ESXi Syslog Redirection to tmp via esxcli

Suspicious Windows Defender Exclusion Enumeration via reg query (via process_creation)

Malicious Windows Defender Exclusion Added via PowerShell (via process_creation)

Malicious BYOVD EDR Kill via Renamed GMER Driver by Agonizing Serpens

Suspicious Windows Defender Real-Time Protection Disabled via Policy Registry by Cephalus Ransomware

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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