Potential Port Monitor or Print Processor Registration Abuse

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.registry-*
endgame-*
logs-m365_defender.event-*

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:

https://www.welivesecurity.com/2020/05/21/no-game-over-winnti-group/

Tags:

Domain: Endpoint
OS: Windows
Use Case: Threat Detection
Tactic: Privilege Escalation
Data Source: Elastic Endgame
Data Source: Elastic Defend
Data Source: Microsoft Defender for Endpoint

Version: 108

Rule authors:

Elastic

Rule license: Elastic License v2

Rule query

edit

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"

Framework: MITRE ATT&CK^TM

Tactic:
- Name: Privilege Escalation
- ID: TA0004
- Reference URL: https://attack.mitre.org/tactics/TA0004/
Technique:
- Name: Boot or Logon Autostart Execution
- ID: T1547
- Reference URL: https://attack.mitre.org/techniques/T1547/
Sub-technique:
- Name: Port Monitors
- ID: T1547.010
- Reference URL: https://attack.mitre.org/techniques/T1547/010/
Sub-technique:
- Name: Print Processors
- ID: T1547.012
- Reference URL: https://attack.mitre.org/techniques/T1547/012/
Tactic:
- Name: Persistence
- ID: TA0003
- Reference URL: https://attack.mitre.org/tactics/TA0003/
Technique:
- Name: Boot or Logon Autostart Execution
- ID: T1547
- Reference URL: https://attack.mitre.org/techniques/T1547/
Sub-technique:
- Name: Port Monitors
- ID: T1547.010
- Reference URL: https://attack.mitre.org/techniques/T1547/010/
Sub-technique:
- Name: Print Processors
- ID: T1547.012
- Reference URL: https://attack.mitre.org/techniques/T1547/012/

« Potential Persistence via Time Provider Modification Potential PowerShell HackTool Script by Author »