Suspicious Add Port Monitor Persistence in Registry (via registry_set)

title: Suspicious Add Port Monitor Persistence in Registry (via registry_set)
id: c8c27a8d-3db4-5554-9448-f2b5b733725b
status: stable
description: This rule detects threat actors may use port monitors to run an adversary supplied DLL during system boot for persistence or privilege escalation. A port monitor can be set through the AddMonitor API call to set a DLL to be loaded at startup.
references:
    - https://attack.mitre.org/techniques/T1547/010/
    - https://github.com/redcanaryco/atomic-red-team/blob/f339e7da7d05f6057fdfcdd3742bfcf365fee2a9/atomics/T1547.010/T1547.010.md
author: Huntrule Team
date: 2026-03-19
tags:
    - attack.privilege-escalation
    - attack.persistence
    - attack.t1547.010
logsource:
    category: registry_set
    product: windows
detection:
    selection:
        TargetObject|contains: '\Control\Print\Monitors\'
        Details|endswith: '.dll'
    filter_optional_cutepdf:
        Image: 'C:\Windows\System32\spoolsv.exe'
        TargetObject|contains: '\Control\Print\Monitors\CutePDF Writer Monitor v4.0\Driver'
        Details: 'cpwmon64_v40.dll'
        User|contains:
            - 'AUTHORI'
            - 'AUTORI'
    filter_optional_monvnc:
        TargetObject|contains: '\Control\Print\Monitors\MONVNC\Driver'
    filter_optional_vnc:
        TargetObject|contains|all:
            - 'Control\Print\Environments\'
            - '\Drivers\'
            - '\VNC Printer'
    condition: selection and not 1 of filter_optional_*
falsepositives:
    - Unknown
level: medium
regression_tests_path: regression_data/rules/windows/registry/registry_set/registry_set_add_port_monitor/info.yml
simulation:
    - type: atomic-red-team
      name: Add Port Monitor persistence in Registry
      technique: T1547.010
      atomic_guid: d34ef297-f178-4462-871e-9ce618d44e50