MITRE ATT&CK Technique
Persistence T1547.010
Description

Adversaries 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 <code>AddMonitor</code> API call to set a DLL to be loaded at startup.(Citation: AddMonitor) This DLL can be located in <code>C:\Windows\System32</code> and will be loaded and run by the print spooler service, `spoolsv.exe`, under SYSTEM level permissions on boot.(Citation: Bloxham) Alternatively, an arbitrary DLL can be loaded if permissions allow writing a fully-qualified pathname for that DLL to the `Driver` value of an existing or new arbitrarily named subkey of <code>HKLM\SYSTEM\CurrentControlSet\Control\Print\Monitors</code>. The Registry key contains entries for the following: * Local Port * Standard TCP/IP Port * USB Monitor * WSD Port

Supported Platforms
Windows
Created

April 29, 2026

Last Updated

April 29, 2026

STIX Data
{'created': '2020-01-24T19:46:27.750Z',
 'created_by_ref': 'identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5',
 'description': 'Adversaries 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 '
                '<code>AddMonitor</code> API call to set a DLL to be loaded at '
                'startup.(Citation: AddMonitor) This DLL can be located in '
                '<code>C:\\Windows\\System32</code> and will be loaded and run '
                'by the print spooler service, `spoolsv.exe`, under SYSTEM '
                'level permissions on boot.(Citation: Bloxham) \n'
                '\n'
                'Alternatively, an arbitrary DLL can be loaded if permissions '
                'allow writing a fully-qualified pathname for that DLL to the '
                '`Driver` value of an existing or new arbitrarily named subkey '
                'of '
                '<code>HKLM\\SYSTEM\\CurrentControlSet\\Control\\Print\\Monitors</code>. '
                'The Registry key contains entries for the following:\n'
                '\n'
                '* Local Port\n'
                '* Standard TCP/IP Port\n'
                '* USB Monitor\n'
                '* WSD Port\n',
 'external_references': [{'external_id': 'T1547.010',
                          'source_name': 'mitre-attack',
                          'url': 'https://attack.mitre.org/techniques/T1547/010'},
                         {'description': 'Bloxham, B. (n.d.). Getting Windows '
                                         'to Play with Itself &#91;PowerPoint '
                                         'slides&#93;. Retrieved November 12, '
                                         '2014.',
                          'source_name': 'Bloxham',
                          'url': 'https://www.defcon.org/images/defcon-22/dc-22-presentations/Bloxham/DEFCON-22-Brady-Bloxham-Windows-API-Abuse-UPDATED.pdf'},
                         {'description': 'Microsoft. (n.d.). AddMonitor '
                                         'function. Retrieved September 12, '
                                         '2024.',
                          'source_name': 'AddMonitor',
                          'url': 'https://learn.microsoft.com/en-us/windows/win32/printdocs/addmonitor'},
                         {'description': 'Russinovich, M. (2016, January 4). '
                                         'Autoruns for Windows v13.51. '
                                         'Retrieved June 6, 2016.',
                          'source_name': 'TechNet Autoruns',
                          'url': 'https://technet.microsoft.com/en-us/sysinternals/bb963902'}],
 'id': 'attack-pattern--43881e51-ac74-445b-b4c6-f9f9e9bf23fe',
 'kill_chain_phases': [{'kill_chain_name': 'mitre-attack',
                        'phase_name': 'persistence'},
                       {'kill_chain_name': 'mitre-attack',
                        'phase_name': 'privilege-escalation'}],
 'modified': '2025-10-24T17:48:42.872Z',
 'name': 'Port Monitors',
 'object_marking_refs': ['marking-definition--fa42a846-8d90-4e51-bc29-71d5b4802168'],
 'revoked': False,
 'spec_version': '2.1',
 'type': 'attack-pattern',
 'x_mitre_attack_spec_version': '3.2.0',
 'x_mitre_contributors': ['Stefan Kanthak',
                          'Travis Smith, Tripwire',
                          'Harun Küßner'],
 'x_mitre_deprecated': False,
 'x_mitre_detection': '',
 'x_mitre_domains': ['enterprise-attack'],
 'x_mitre_is_subtechnique': True,
 'x_mitre_modified_by_ref': 'identity--c78cb6e5-0c4b-4611-8297-d1b8b55e40b5',
 'x_mitre_platforms': ['Windows'],
 'x_mitre_version': '1.3'}
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