TA0003 · PERSISTENCE
Print Processors
Adversaries may abuse print processors to run malicious DLLs during system boot for persistence and/or privilege escalation. Print processors are DLLs that are loaded by the print spooler service, spoolsv.exe, during boot.
Detect it with
Monitor process API calls to AddPrintProcessor and GetPrintProcessorDirectory . New print processor DLLs are written to the print processor directory.
Why it matters on shift
Print Processors 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