Potential Port Monitor or Print Processor Registration Abuse

edit

Potential Port Monitor or Print Processor Registration Abuse

edit

Identifies port monitor and print processor registry modifications. Adversaries may abuse port monitor and print processors to run malicious DLLs during system boot that will be executed as SYSTEM for privilege escalation and/or persistence, if permissions allow writing a fully-qualified pathname for that DLL.

Rule type: eql

Rule indices:

  • logs-endpoint.events.*

Severity: medium

Risk score: 47

Runs every: 5m

Searches indices from: now-9m (Date Math format, see also Additional look-back time)

Maximum alerts per execution: 100

References:

Tags:

  • Elastic
  • Host
  • Windows
  • Threat Detection
  • Privilege Escalation

Version: 101

Rule authors:

  • Elastic

Rule license: Elastic License v2

Rule query

edit
registry where event.type in ("creation", "change") and
  registry.path : ("HKLM\\SYSTEM\\*ControlSet*\\Control\\Print\\Monitors\\*",
    "HKLM\\SYSTEM\\*ControlSet*\\Control\\Print\\Environments\\Windows*\\Print Processors\\*") and
  registry.data.strings : "*.dll" and
  /* exclude SYSTEM SID - look for changes by non-SYSTEM user */
  not user.id : "S-1-5-18"

Framework: MITRE ATT&CKTM