Malicious Winlogon Shell Hijack Loading MSBuild

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1127.001MSBuild
Persistence
- T1547.004Winlogon Helper DLL
Priv Esc
- T1547.004Winlogon Helper DLL
Defense Evasion
- T1127.001MSBuild
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the Winlogon Shell value being altered to reference MSBuild which the Dark Pink APT uses to persist and proxy execute code at logon through a trusted developer binary. The Shell key should only launch explorer.exe so any MSBuild reference signals abuse. It matters because it combines stealthy persistence with signed binary proxy execution.

Reporting behind it

Related detections9 linkedT1127.001 — drag to rearrange

Proxy Execution via MSBuild Running Inline Task XML

MSBuild Executing Non-Project File or Remote Payload

Antivirus Check and Remote Loader Retrieval in LNK Command Chain

Suspicious MSBuild Execution From Office or Archive Extraction Context (via process_creation)

Malicious Winlogon Shell or Userinit Persistence Modification (via registry_set)

Suspicious Command Prompt Spawned by Winlogon

Suspicious Winlogon Loading Keyboard Layout DLL kbdus1.dll

Malicious Winlogon Shell Persistence Modification (via registry_set)

Suspicious MSBuild Execution from Writable Directory (via process_creation)

Malicious Winlogon Shell Hijack Loading MSBuild

Pivot detection · T1127.001 · 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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