TA0005 · DEFENSE EVASION
Regsvcs/Regasm
Adversaries may abuse Regsvcs and Regasm to proxy execution of code through a trusted Windows utility. Regsvcs and Regasm are Windows command-line utilities that are used to register .NET Component Object Model (COM) assemblies.
Detect it with
Use process monitoring to monitor the execution and arguments of Regsvcs.exe and Regasm.exe. Compare recent invocations of Regsvcs.exe and Regasm.exe with prior history of known good arguments and executed binaries to determine anomalous and potentially adversarial activity.
Why it matters on shift
Regsvcs/Regasm is one of the concrete ways adversaries achieve defense evasion. Recognising it in telemetry lets you name the technique in your ticket and pivot to what came before and after.
What to look for next
After defense evasion, the next tactic is usually Credential Access. Search your telemetry for the transition before closing the ticket.
Kill-chain context