Suspicious RegAsm or RegSvcs Spawned by Script Host (via process_creation)

ATT&CK techniques

Priv Esc → Defense Evasion

Recon
Resource Dev
Initial Access
Execution
Persistence
Priv Esc
- T1055Process Injection
Defense Evasion
- T1055Process Injection
- T1218System Binary Proxy Execution
Cred Access
Discovery
Lateral Movement
Collection
C2
Exfiltration
Impact

What it detects

This rule detects RegAsm.exe or RegSvcs.exe launched by a script host such as PowerShell, wscript, or cscript, the injection target abused in the Cascading Shadows phishing chain. The actor hollows these signed .NET utilities to run Agent Tesla, Remcos, or XLoader while evading defenses through trusted binary proxy execution.

Reporting behind it

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Suspicious RegAsm or RegSvcs Spawned by Script Host (via process_creation)

Pivot detection · T1218 · 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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