ATT&CK coverage › Technique

Subvert Trust Controls: Install Root Certificate T1553.004

Adversaries may install a root certificate on a compromised system to avoid warnings when connecting to adversary controlled web servers. Root certificates are used in public key cryptography to identify a root certificate authority (CA). When a root certificate is installed, the system or application will trust certificates in the root's chain of trust that have been signed by the root certificate. Certificates are commonly used for establishing secure TLS/SSL communications within a web browser. When a user attempts to browse a website that presents a certificate that is not trusted an error message will be displayed to warn the user of the security risk. Depending on the security settings, the browser may not allow the user to establish a connection to the website.

Events covered

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

ProviderEvent IDTitle
Sysmon1Process creation
Sysmon13RegistryEvent (Value Set)
Security-Auditing4688A new process has been created.
CertificationAuthority53Active Directory Certificate Services denied request Name because RequestId.
PowerShell4104Creating Scriptblock text (MessageNumber of MessageTotal).

Authoring guide

Patterns shared across the 8 rules above: which fields they filter on, what specific values they look for, and what they exclude. Field names are normalized 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 (7 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
CommandLine4match 4root, /add, -addstore, \Desktop\, -FilePath
Image2ends_with 2\CertMgr.exe, \certutil.exe
OriginalFileName2eq 2CERTMGT.EXE, CertUtil.exe
ScriptBlockText2match 2Move-Item, Cert:\LocalMachine\Root, Import-Certificate, X509Enrollment.CBinaryConverter, 884e2002-217d-11da-b2a4-000e7bbb2b09
Provider_Name1eq 1Microsoft-Windows-CertificationAuthority
registry_path1eq 1"*\\certificates\\*"
registry_value_name1eq 1"Blob"

Top indicator values (26 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.

FieldKindValueRules (here)Corpus reach
CommandLinematchroot22
Provider_NameeqMicrosoft-Windows-CertificationAuthority1
OriginalFileNameeqCERTMGT.EXE1
CommandLinematch/add13
Imageends_with\CertMgr.exe1
CommandLinematch-addstore1
OriginalFileNameeqCertUtil.exe113
Imageends_with\certutil.exe134
ScriptBlockTextmatchMove-Item1
ScriptBlockTextmatchImport-Certificate1
ScriptBlockTextmatchCert:\LocalMachine\Root1
CommandLinematch\Desktop\111
CommandLinematch\AppData\Local\Temp\116
CommandLinematchImport-Certificate1
CommandLinematch\Perflogs\1
CommandLinematch\Downloads\112
CommandLinematchCert:\LocalMachine\Root1
CommandLinematch -FilePath 1
CommandLinematch:\Users\Public\114
CommandLinematch:\Windows\TEMP\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.

Sigma 7 rules

Splunk 1 rule