Subvert Trust Controls: SIP and Trust Provider Hijacking T1553.003

Tactic: Defense Impairment

Adversaries may tamper with SIP and trust provider components to mislead the operating system and application control tools when conducting signature validation checks. In user mode, Windows Authenticode digital signatures are used to verify a file's origin and integrity, variables that may be used to establish trust in signed code (ex: a driver with a valid Microsoft signature may be handled as safe). The signature validation process is handled via the WinVerifyTrust application programming interface (API) function, which accepts an inquiry and coordinates with the appropriate trust provider, which is responsible for validating parameters of a signature.

Events covered

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

Authoring guide

Patterns shared across the 7 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 (9 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
Details4contains 2, ends_with 1, eq 1.dll, (empty), C:\Windows\System32\PsfSip.dll, WINTRUST.DLL, \$dll
TargetObject4contains 3, ends_with 1, wildcard 1*\software\microsoft\cryptography\oid\encodingtype..., *\software\microsoft\cryptography\providers\trust\finalpo..., *\software\wow6432node\microsoft\cryptography\oid\encodin..., \$dll, \cryptsipdll
registry_value_name2eq 1, in 1Dll, $DLL, $Dll
Dll1eq 1*\\*.dll
EventID1eq 181
Image1eq 1c:\windows\system32\poqexec.exe
event.type1eq 1change
registry_path1in 1*\\SOFTWARE\\Microsoft\\Cryptography\\OID\\EncodingType*, *\\SOFTWARE\\Microsoft\\Cryptography\\Providers\\*, *\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\OID\\E...
sourcetype1eq 1PwSh:SubjectInterfacePackage

Top indicator values (34 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
TargetObjectcontains
\software\microsoft\cryptography\oid\encodingtype
22
TargetObjectcontains
\software\microsoft\cryptography\providers\
22
TargetObjectcontains
\software\wow6432node\microsoft\cryptography\oid\encodingtype
22
TargetObjectcontains
\software\wow6432node\microsoft\cryptography\providers\
22
TargetObjectcontains
\$dll
1
TargetObjectcontains
\cryptsipdll
1
TargetObjectcontains
\dll
1
TargetObjectcontains
\software\microsoft\cryptography\providers\{
1
Detailscontains
(empty)
1
Detailscontains
.dll
15
Detailscontains
\$dll
1
Detailscontains
\dll
1
Detailsends_with
.dll
18
Detailseq
C:\Windows\System32\PsfSip.dll
1
Detailseq
WINTRUST.DLL
1
Detailseq
mso.dll
1
Dlleq
*\\*.dll
1
EventIDeq
81
1
Imageeq
c:\windows\system32\poqexec.exe
1
TargetObjectends_with
\seed
1
TargetObjectwildcard
*\software\microsoft\cryptography\oid\encodingtype...
1
TargetObjectwildcard
*\software\microsoft\cryptography\providers\trust\finalpolicy\{*}\$dll
1
TargetObjectwildcard
*\software\wow6432node\microsoft\cryptography\oid\encodingtype...
1
TargetObjectwildcard
*\software\wow6432node\microsoft\cryptography\providers\trust\finalpolicy\{*}\$dll
1
event.typeeq
change
177
registry_pathin
*\\SOFTWARE\\Microsoft\\Cryptography\\OID\\EncodingType*
1
registry_pathin
*\\SOFTWARE\\Microsoft\\Cryptography\\Providers\\*
1
registry_pathin
*\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\OID\\EncodingType*
1
registry_pathin
*\\SOFTWARE\\WOW6432Node\\Microsoft\\Cryptography\\Providers\\*
1
registry_value_nameeq
$Dll
1

Exclusions (8 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
Detailseq
WINTRUST.DLL
2
Detailseq
mso.dll
2
Detailseq
C:\Windows\System32\PsfSip.dll
1
Detailscontains
(empty)
1
Imageeq
c:\windows\system32\poqexec.exe
1
TargetObjectcontains
\cryptsipdll
1
process_nameeq
msiexec.exe
1
process_nameeq
regsvr32.exe
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)

Sigma 3 rules

Elastic 1 rule

Splunk 3 rules