Elastic Security Detection Rules

Potential Port Monitor or Print Processor Registration Abuse

Last updated 7 months ago on 2025-01-15
Created 5 years ago on 2021-01-21

About

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.
Tags
Domain: EndpointOS: WindowsUse Case: Threat DetectionTactic: Privilege EscalationData Source: Elastic EndgameData Source: Elastic DefendData Source: Microsoft Defender for EndpointLanguage: eql
Severity
medium
Risk Score
47
MITRE ATT&CK™

Privilege Escalation (TA0004)(opens in a new tab or window)

↳ Boot or Logon Autostart Execution (T1547)(opens in a new tab or window)

Persistence (TA0003)(opens in a new tab or window)

↳ Boot or Logon Autostart Execution (T1547)(opens in a new tab or window)

License
Elastic License v2(opens in a new tab or window)

Definition

Rule Type
Event Correlation Rule
Integration Pack
Prebuilt Security Detection Rules
Index Patterns
logs-endpoint.events.registry-*endgame-*logs-m365_defender.event-*
Related Integrations

endpoint(opens in a new tab or window)

m365_defender(opens in a new tab or window)

Query
registry where host.os.type == "windows" and event.type == "change" and
  registry.path : (
      "HKLM\\SYSTEM\\*ControlSet*\\Control\\Print\\Monitors\\*",
      "HKLM\\SYSTEM\\*ControlSet*\\Control\\Print\\Environments\\Windows*\\Print Processors\\*",
      "\\REGISTRY\\MACHINE\\SYSTEM\\*ControlSet*\\Control\\Print\\Monitors\\*",
      "\\REGISTRY\\MACHINE\\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"

Install detection rules in Elastic Security

Detect Potential Port Monitor or Print Processor Registration Abuse in the Elastic Security detection engine by installing this rule into your Elastic Stack.

To setup this rule, check out the installation guide for Prebuilt Security Detection Rules(opens in a new tab or window).