Potential Port Monitor or Print Processor Registration Abuse

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Potential Port Monitor or Print Processor Registration Abuseedit

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: 5 minutes

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: 100 (version history)

Added (Elastic Stack release): 7.12.0

Last modified (Elastic Stack release): 8.5.0

Rule authors: Elastic

Rule license: Elastic License v2

Rule queryedit

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"

Threat mappingedit

Framework: MITRE ATT&CKTM

Rule version historyedit

Version 100 (8.5.0 release)
  • Formatting only
Version 3 (8.4.0 release)
  • Formatting only
Version 2 (8.1.0 release)
  • Updated query, changed from:

    registry where event.type in ("creation", "change") and
    registry.path :
    ("HKLM\\SYSTEM\\*ControlSet*\\Control\\Print\\Monitors\\*", "HLLM\
    \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"