tfMITRE ATT&CK sub-technique

Print Processors T1547.012

sub-technique of T1547 Boot or Logon Autostart Execution

Tactics: Persistence, Privilege Escalation
Platform: Windows
Version: 1.2
Created: 05 October 2020
Last modified: 24 October 2025
Contributors: Mathieu Tartare, ESET; Tahseen Bin Taj

Adversaries may abuse print processors to run malicious DLLs during system boot for persistence and/or privilege escalation. Print processors are DLLs that are loaded by the print spooler service, spoolsv.exe, during boot.[1]

ReconResource DevInitial AccessExecutionPersistencePriv EscStealthDef ImpairmentCred AccessDiscoveryLateral MoveCollectionC2ExfiltrationImpact

Threat groups45th pct

Threat groups45th percentile · 55% of ATT&CK techniques have more threat groups attributed.

CampaignsNone recorded

CampaignsNone recorded · 54% of ATT&CK techniques have none either.

Tools & malware51st pct

Tools & malware51st percentile · 51% of ATT&CK techniques have this many tools implementing them or fewer.

Detection rules69th pct

Detection rules69th percentile · 69% of ATT&CK techniques have this many detection rules written or fewer.

Print Processors MITRE reference T1547.012

45th pctamong all ATT&CK techniques for number of groups

1 group has been recorded using this technique. Newest first; each entry carries MITRE’s procedure text and a link to the group’s full record. Click a name to filter the rules below.

Earth LuscaG1006 ↗

Has added the Registry key HKLM\SYSTEM\ControlSet001\Control\Print\Environments\Windows x64\Print Processors\UDPrint” /v Driver /d “spool.dll /f to load malware as a Print Processor.1

created 2022-07-011 referenceaka TAG-22

All 1 groups for this technique

2 software entries are documented implementing this technique. MITRE files each as a tool or as malware; newest first, then by how many groups carry them.

GelsemiumS0666 ↗

Can drop itself in C:\Windows\System32\spool\prtprocs\x64\winprint.dll to be loaded automatically by the spoolsv Windows service.1

created 2021-11-30MALWARE

PipeMonS0501 ↗

The PipeMon installer has modified the Registry key HKLM\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows x64\Print Processors to install PipeMon as a Print Processor.1

created 2020-08-24MALWAREcarried by 1 group

All 2 software entries for this technique

Offense vs defense T1547.012

Is defensive coverage keeping up with adversary use? Eight counts, each ranked against all 697 ATT&CK techniques. Attack sits left, defense right, so a shape leaning left means adversaries are better documented here than defenders are equipped. Hover any spoke for its percentile and the share of techniques that have more. The timeline below shows when each side arrived.

How it got here

Range

Adversary activity (campaign spans) over cumulative rule output. Each source is plotted independently from zero, so neither line includes the other. Campaign dates are year-granularity.

Campaigns · 0Sigma rules (cumulative) · 0Splunk ESCU (cumulative) · 7

first rule: 2021 Q3

Print Processors detection strategy DET0026

MITRE names one behaviour worth catching for this technique and breaks it into 1 analytic, one per platform. Each carries the log sources it needs and the fields you tune per environment.

Windows Detection Strategy for T1547.012 - Print Processor DLL Persistence

Enterprise

1 platform

AN0074 · Windows

Correlated registry modifications under Print Processors path, followed by DLL file creation within the system print processor directory, and DLL load by spoolsv.exe. Malicious execution often occurs during service restart or system boot, with SYSTEM-level privileges.

Log sources

The data this analytic draws on. You do not need every component — each one you already collect covers part of it. Each links to its ATT&CK record.

Data component	Name	Channel
Module LoadDC0016	WinEventLog:Sysmon	EventCode=7
Process AccessDC0035	WinEventLog:Sysmon	EventCode=10
File CreationDC0039	WinEventLog:Sysmon	EventCode=11
Windows Registry Key ModificationDC0063	WinEventLog:Sysmon	EventCode=13, 14

Tunable fields

MITRE calls these the analytic’s mutable elements: the thresholds and filters you set for your own environment.

Field	What you tune
TimeWindow	Correlate Registry + DLL Write + Module Load within a short boot or spooler restart window (e.g., 5 minutes).
PrintProcessorDirectory	System-specific path derived from GetPrintProcessorDirectory API call; may differ across Windows versions or configurations.
DLLNamePattern	Some environments may use custom or non-standard DLL naming conventions for print processors. Allowlist known values.
SignedImageValidation	Check Authenticode signature and issuer chain for loaded DLLs to reduce false positives.
ServiceRestartTrigger	Monitor for spoolsv.exe restart events that trigger malicious print processor loading.

User Account ManagementM1018

Limit user accounts that can load or unload device drivers by disabling SeLoadDriverPrivilege.

Tests1ExecutorsPowerShell 1Need elevation1 of 1Have prerequisites0Have cleanup1Platformswindows

Test

Platform

Executor

Elevation

Prereqs

Cleanup

Ref

Print Processors

windows

PowerShell

Required

—

Yes

Establishes persistence by creating a new print processor registry key under HKEY_LOCAL_MACHINE\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows x64\Print Processors. The new print processor will point to a DLL which will be loaded by the spooler service after a reboot. The DLL will then create the file AtomicTest.txt in C:\Users\Public\ as validation that the test is successful. Note: The test assumes a x64 Windows operating system. The payload source code is based on a blog post by stmxcsr: https://stmxcsr.com/persistence/print-processor.html

Input arguments

Name	Type	Default	Description
restart	integer	0	set to 1 if you want the computer to reboot as part of the test

Attack command

if( $(get-service -Name spooler).StartType -eq "Disabled") {Set-Service -Name "spooler" -StartupType Automatic}
net stop spooler
Copy-Item "$PathToAtomicsFolder\T1547.012\bin\AtomicTest.dll" C:\Windows\System32\spool\prtprocs\x64\AtomicTest.dll
reg add "HKLM\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows x64\Print Processors\AtomicRedTeam" /v "Driver" /d "AtomicTest.dll" /t REG_SZ /f
net start spooler
if(#{restart}){
  Restart-Computer
}

Cleanup command

net stop spooler
rm -force C:\Windows\System32\spool\prtprocs\x64\AtomicTest.dll -ErrorAction SilentlyContinue
rm -force C:\Users\Public\AtomicTest.txt -ErrorAction SilentlyContinue
remove-item "HKLM:\SYSTEM\CurrentControlSet\Control\Print\Environments\Windows x64\Print Processors\AtomicRedTeam" -Force -ErrorAction SilentlyContinue
net start spooler

GUID4c7ef866-717a-4d82-8b2b-c5673b4205a6

Tests from Atomic Red Team (MIT licence) · technique definition

Print Processors detections T1547.012

7 rules are mapped to this technique. Parent techniques also include their sub-techniques’ rules. Click a slice or key entry to filter the table.

69th pctamong all ATT&CK techniques for number of rules

Product

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