Suspicious RegAsm Execution Spawned by Script Host for Process Hollowing (via process_creation)

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1055.012Process Hollowing
Defense Evasion
- T1055.012Process Hollowing
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects the .NET RegAsm utility being launched by a script host or PowerShell, a pattern used by AsyncRAT to hollow the trusted RegAsm.exe process with the NewPE2 injector. RegAsm is a developer registration tool and is not normally started by wscript, cscript, mshta or powershell. This parent-child relationship exposes the injection target used to run the final RAT payload.

Reporting behind it

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Suspicious RegAsm Execution Spawned by Script Host for Process Hollowing (via process_creation)

Pivot detection · T1055.012 · 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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