Suspicious Microsoft Defender Exclusion Added via PowerShell

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 PowerShell adding a Microsoft Defender exclusion path, a defense-evasion step performed by Pure Crypter before deploying its payload. Attackers exclude their staging directories from antivirus scanning so subsequent malicious files execute undetected, making unexpected Add-MpPreference exclusions a reliable evasion indicator.

Reporting behind it

Related detections9 linkedT1685 — drag to rearrange

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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 Microsoft Defender Exclusion Added via PowerShell

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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