Boot or Logon Autostart Execution: Print Processors T1547.012

Tactics: Persistence, Privilege Escalation

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.

Events covered

10 catalog events are tagged with this technique by at least one rule.

Authoring guide

Patterns shared across the 8 rules above: which fields they filter on, what specific values they look for, and what they exclude. The catalog normalizes field names across vendors so Sigma's Image, Elastic's process.name, and Splunk's process_name collapse into one row. Each rule contributes at most once per row.

Fields filtered most (16 distinct)

The fields most rules look at when detecting this technique. The How column shows the operators authors use (eq, wildcard, regex_match, match) and how often each appears. Sample values are concrete examples to start from, not an exhaustive list.

FieldRulesHowSample values
EventID4eq 411, 316, 4909, 7, 808
process_name3eq 3spoolsv.exe, rundll32.exe
TargetFilename2contains 2\\spool\\drivers\\x64\\
file_name2ends_with 2.dll
Details1ends_with 1.dll
Image1ends_with 1\\spoolsv.exe
ImageLoaded1contains 1, ends_with 1.dll, \\windows\\system32\\spool\\drivers\\x64\\
Message1contains 1.dll., kernelbase.dll,, unidrv.dll,
OriginalFileName1eq 1rundll32.exe
TargetObject1wildcard 1\registry\machine\system\*controlset*\control\print\envir..., \registry\machine\system\*controlset*\control\print\monitors\*, hklm\system\*controlset*\control\print\environments\windo...
aws::errorCode1eq 10x45A
category1eq 1Adding a printer driver
countImgloaded1ge 13
event.type1eq 1change
parent_process_name1eq 1spoolsv.exe

Top indicator values (27 distinct)

Specific (field, operator, value) combinations the rules check for, ranked by how many rules under this technique use each one. The Corpus reach column counts how many rules across the entire catalog (any technique) check the same combination. High numbers point to widely-used indicators that are likely noisy on their own; combine them with another condition for useful signal. Blank means the combination is specific to rules under this technique. Click a value to expand the rules under this technique that use it.

FieldKindValueRules (here)Corpus reach
TargetFilenamecontains
\\spool\\drivers\\x64\\
22
file_nameends_with
.dll
26
process_nameeq
spoolsv.exe
25
process_nameeq
rundll32.exe
160
Detailsends_with
.dll
18
EventIDeq
11
123
EventIDeq
316
12
EventIDeq
4909
1
EventIDeq
7
139
EventIDeq
808
1
Imageends_with
\\spoolsv.exe
12
ImageLoadedcontains
\\windows\\system32\\spool\\drivers\\x64\\
1
ImageLoadedends_with
.dll
16
Messagecontains
.dll.
1
Messagecontains
kernelbase.dll,
1
Messagecontains
unidrv.dll,
1
OriginalFileNameeq
rundll32.exe
162
TargetObjectwildcard
\registry\machine\system\*controlset*\control\print\environments\windows*\pri...
1
TargetObjectwildcard
\registry\machine\system\*controlset*\control\print\monitors\*
1
TargetObjectwildcard
hklm\system\*controlset*\control\print\environments\windows*\print processors\*
1
TargetObjectwildcard
hklm\system\*controlset*\control\print\monitors\*
1
aws::errorCodeeq
0x45A
12
categoryeq
Adding a printer driver
1
countImgloadedge
3
1
event.typeeq
change
177
parent_process_nameeq
spoolsv.exe
15
registry_pathcontains
\\control\\print\\environments\\windows x64\\print processors
1

Exclusions (1 distinct)

Field/operator/value combinations excluded by rules under this technique (top-level not() clauses), sorted by how many rules exclude each. These are the false-positive paths the community has learned to filter out. A new rule that ignores the high-count entries here will likely fire on the same noisy paths. Click a value to expand the rules under this technique that exclude it.

FieldKindValueRules excluding
user.ideq
S-1-5-18
1

Rules under this technique

Every rule in the catalog tagged with this technique, grouped by vendor. Click a rule title for its full predicates, exclusions, and indicators.

Platform (all)
Domain (all)

Elastic 1 rule

Splunk 7 rules