Suspicious App Domain Manager Injection via Environment Variables

ATT&CK techniques

Execution → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
- T1574.001DLL
Persistence
- T1574.001DLL
Priv Esc
- T1055Process Injection
- T1574.001DLL
Defense Evasion
- T1055Process Injection
- T1574.001DLL
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects processes started with the APPDOMAIN_MANAGER_ASM or APPDOMAIN_MANAGER_TYPE environment variables set, the environment-driven form of App Domain Manager injection that forces a .NET runtime to load an attacker-specified assembly at startup. These variables are honored by the CLR to override the default app domain manager, hijacking execution inside a trusted signed binary. Their presence in a process environment is highly abnormal and indicates deliberate .NET execution hijacking.

Reporting behind it

Related detections9 linkedT1574.001 — drag to rearrange

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Suspicious App Domain Manager Injection via Environment Variables

Pivot detection · T1574.001 · 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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