TA0003 · PERSISTENCE
Password Filter DLL
Adversaries may register malicious password filter dynamic link libraries (DLLs) into the authentication process to acquire user credentials as they are validated.
Detect it with
Monitor for new, unfamiliar DLL files written to a domain controller and/or local computer.
Why it matters on shift
Password Filter DLL is one of the concrete ways adversaries achieve persistence. 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 persistence, the next tactic is usually Privilege Escalation. Search your telemetry for the transition before closing the ticket.
Kill-chain context