Develop Capabilities: Digital Certificates T1587.003

Tactic: Resource Development

Adversaries may create self-signed SSL/TLS certificates that can be used during targeting. SSL/TLS certificates are designed to instill trust. They include information about the key, information about its owner's identity, and the digital signature of an entity that has verified the certificate's contents are correct. If the signature is valid, and the person examining the certificate trusts the signer, then they know they can use that key to communicate with its owner. In the case of self-signing, digital certificates will lack the element of trust associated with the signature of a third-party certificate authority (CA).

Events covered

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

Authoring guide

Patterns shared across the 1 rule 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 (3 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
CommandLine1contains 1, in 1*%AppData%*, *%Public%*, *%Temp%*
OriginalFileName1eq 1certutil.exe
process_name1eq 1certutil.exe

Top indicator values (13 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
CommandLinecontains
-addstore
12
CommandLinecontains
root
13
CommandLinein
*%AppData%*
12
CommandLinein
*%Public%*
12
CommandLinein
*%Temp%*
12
CommandLinein
*%tmp%*
12
CommandLinein
*:\\PerfLogs\\*
12
CommandLinein
*:\\Windows\\Temp\\*
12
CommandLinein
*\\AppData\\Local\\Temp\\*
12
CommandLinein
*\\ProgramData\\*
13
CommandLinein
*\\Users\\Public\\*
14
OriginalFileNameeq
certutil.exe
121
process_nameeq
certutil.exe
122

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)

Splunk 1 rule