Subvert Trust Controls T1553

Tactic: Defense Impairment

Adversaries may undermine security controls that will either warn users of untrusted activity or prevent execution of untrusted programs. Operating systems and security products may contain mechanisms to identify programs or websites as possessing some level of trust. Examples of such features would include a program being allowed to run because it is signed by a valid code signing certificate, a program prompting the user with a warning because it has an attribute set from being downloaded from the Internet, or getting an indication that you are about to connect to an untrusted site.

Events covered

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

Authoring guide

Patterns shared across the 60 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 (49 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
Image14ends_with 9, is_not_null 2, contains 1, eq 1, in 1, starts_with 1\certutil.exe, *\\ai_stubs\\aistubx64.exe, *\\ai_stubs\\aistubx64elevated.exe, *\\ai_stubs\\aistubx86.exe, /apt
event.type12eq 10, in 2start, change, process_started, deletion
CommandLine9contains 9com.apple.quarantine, root, -filepath , nc, --install
EventType9eq 7, in 2exec, ProcessRollup2, cs_invalidated, exec_event, extended_attributes_delete
host.os.type9eq 9
EventID8eq 823, 400, 4103, 4104, 4663
process_name8eq 6, in 3agentactivationruntimestarter.exe, agentservice.exe, aggregatorhost.exe, bash, bcdedit.exe
OriginalFileName6eq 6popupwrapper.exe, bcdedit.exe, boinc.exe, certmgt.exe, certutil.exe
Details5contains 2, eq 2, ends_with 1.dll, (empty), 0, 0x00000000, 0x00000001
ScriptBlockText5contains 5-imagepath , ):\, -path , .driveletter, 884e2002-217d-11da-b2a4-000e7bbb2b09
TargetObject5contains 3, wildcard 2, ends_with 1*\software\microsoft\cryptography\oid\encodingtype..., *\software\microsoft\cryptography\providers\trust\finalpo..., *\software\wow6432node\microsoft\cryptography\oid\encodin..., \$dll, \cryptsipdll
process.args5eq 4, contains 1, in 1, match 1, wildcard 1-*a*, --directory, --download, --master-disable, --output
registry_value_name5eq 4, in 1Blob, Dll, $DLL, $Dll, BehaviorOnFailedVerify
TargetFilename4ends_with 1, match 1, starts_with 1, wildcard 1(?i)\x5cdevice\x5ccdrom, /applications/*, /etc/ssl/certs/, /private/tmp/*, /private/var/tmp/*
ParentImage3ends_with 2, is_not_null 1/script editor, \razerinstaller.exe

Top indicator values (3538 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
event.typeeq
start
6606
event.typeeq
change
377
CommandLinecontains
com.apple.quarantine
22
CommandLinecontains
root
23
EventTypeeq
exec
2171
EventTypein
exec
2171
Flagseq
8388608
22
HasFullTrusteq
true
22
Imageends_with
/xattr
22
Imageends_with
\certutil.exe
243
OriginalFileNameeq
popupwrapper.exe
22
ScriptBlockTextcontains
-imagepath
22
ScriptBlockTextcontains
mount-diskimage
22
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
event.typein
process_started
240
event.typein
start
242
parent_process_namewildcard
bash
27
parent_process_namewildcard
osascript
26
parent_process_namewildcard
sh
27
parent_process_namewildcard
zsh
27
process.code_signature.existseq
false
219
process.code_signature.trustedeq
false
218
process_nameeq
bcdedit.exe
27
process_nameeq
certutil.exe
222
process_nameeq
cmd.exe
277
process_nameeq
cscript.exe
225
process_nameeq
expand.exe
24

Exclusions (246 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.

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 28 rules

Elastic 17 rules

Splunk 13 rules

Kusto 1 rule

Panther 1 rule