T1547.010: Port Monitors
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 AddMonitor API call to set a DLL to be loaded at startup.[1] This DLL can be located in C:\Windows\System32 and will be loaded and run by the print spooler service, `spoolsv.exe`, under SYSTEM level permissions on boot.[2]
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 HKLM\SYSTEM\CurrentControlSet\Control\Print\Monitors. The Registry key contains entries for the following:
* Local Port * Standard TCP/IP Port * USB Monitor * WSD Port
Security context for executives and security teams
T1547.010: Port Monitors describes 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 AddMonitor API call to set a DLL to be loaded at startup.(Citation: AddMonitor) This DLL can be located in C:\Windows\System32 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 path...
Executive priority
T1547.010: Port Monitors is an official MITRE ATT&CK technique. Glexia treats it as defensive behavior context for prioritizing monitoring, control validation, and response planning without using the object by itself as an attribution claim.
Technical view
Security teams should validate T1547.010: Port Monitors by reviewing the official ATT&CK relationships, mapped tactics (persistence, privilege-escalation), supported platforms (Windows), and available local telemetry before making detection or mitigation decisions.
Likely telemetry
- Official ATT&CK relationships and object metadata
- Identity, privilege, and authentication events
- Network, endpoint, and security-tool telemetry
Detection direction
- Validate whether T1547.010: Port Monitors appears in your detection coverage and tabletop scenarios.
- Use the object to align executive risk language with SOC, incident response, and detection engineering work.
- Do not treat ATT&CK relationship context as attribution without corroborating evidence.
Mitigation priorities
- Map the object to existing controls and identify missing telemetry or response ownership.
- Prioritize mitigations that reduce exposure on the listed platforms and tactics.
- Review adjacent ATT&CK relationships before changing policy, detections, or reporting language.
Additional notes and limits
Baseline Glexia take generated from the official MITRE ATT&CK STIX object, source hash, tactics, platforms, and detection fields. It is safe to replace with a richer model-generated take for the same source hash later.
This baseline take is source-grounded and schema-validated, but it does not include environment-specific telemetry, incident evidence, or threat-intelligence corroboration.
Generated from the cited source records. This long-tail analysis has not been individually reviewed by a named human.
Port Monitors
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 AddMonitor API call to set a DLL to be loaded at startup.[1] This DLL can be located in C:\Windows\System32 and will be loaded and run by the print spooler service, `spoolsv.exe`, under SYSTEM level permissions on boot.[2]
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 HKLM\SYSTEM\CurrentControlSet\Control\Print\Monitors. The Registry key contains entries for the following:
* Local Port * Standard TCP/IP Port * USB Monitor * WSD Port
How security teams should use this page
Treat this object as behavior context, not an attribution claim. Validate the related groups, software, data sources, and mitigations against official ATT&CK relationships and your own telemetry before making control-coverage decisions.
Related techniques
This mirrors the MITRE pattern of making group, software, campaign, and technique relationships scannable. Relationship notes come from mirrored ATT&CK relationship text when available.
| Domain | ID | Name | Relationship / procedure |
|---|---|---|---|
| Enterprise | T1013 | Port Monitors | Port Monitors revoked by this object. |
| Enterprise | T1547 | Boot or Logon Autostart Execution | This object subtechnique of Boot or Logon Autostart Execution. |
All related ATT&CK context
Object version and sync metadata
The fields below describe the current mirrored snapshot. When Glexia retains multiple ATT&CK source imports, you can open the table to compare the same object across releases (hashes and MITRE timestamps). For MITRE’s own release notes and roadmap, see ATT&CK resources — Updates.
Imported snapshots across ATT&CK releases(2)
| Release | Bundle imported | Object version | Modified | Status | Raw hash |
|---|---|---|---|---|---|
| 19.2 | 1.3 | Current bundle | 6c371dd444ad… | ||
| 19.1 | 1.3 | Older bundle | 6c371dd444ad… |
Mirrored ATT&CK source object
The raw object is retained through the mirrored ATT&CK source bundle and object hash. The raw endpoint returns the exact object from the mirrored bundle when available.
External references and citations
MITRE external references are preserved separately from Glexia analysis so citations remain traceable to their original source records.
- [1]AddMonitor
Microsoft. (n.d.). AddMonitor function. Retrieved September 12, 2024.
Open source URL - [2]Bloxham
Bloxham, B. (n.d.). Getting Windows to Play with Itself [PowerPoint slides]. Retrieved November 12, 2014.
Open source URL - [3]TechNet Autoruns
Russinovich, M. (2016, January 4). Autoruns for Windows v13.51. Retrieved June 6, 2016.
Open source URL - [4]mitre-attackT1547.010Open source URL
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