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MITRE D3FEND™ Learning Center

D3-ACA — Active Certificate Analysis

Actively collecting PKI certificates by connecting to the server and downloading its server certificates for analysis.

6Enterprise inferred
1Parent technique
1Related artifact
1Source reference

Detect · D3FEND ontology 1.6.0 · Active

Open official technique ↗
Official D3FEND definition

Definition

Actively collecting PKI certificates by connecting to the server and downloading its server certificates for analysis.

Official D3FEND knowledge-base content

How it works

Analysis of server certificates using active methods to detect if certificates have been misconfigured or spoofed by using elements of the certificate, certificate authorities and signatures.

Certificate validity analysis

This can be accomplished by verifying the digital signature on certificate.

Certificate path analysis

The client's browser can perform path verification to ensure that the server's certificate contains a valid trust anchor.

Certificate configuration analysis

Some browsers can be configured to implement the key-usage extensions contained certificates. This can help to prevent a certificate from being misused.

Certificate revocation status analysis

Using either Certificate Revocation Lists (CRLs) or Online Certificate Status Protocol (OCSP) to determine the revocation status. OCSP Stapling, binding the status with the certificate, helps to mitigate potential delay in status verifications.

Considerations

  • Management of the PKI across the enterprise typically requires automation to maintain scalability and flexibility
  • If the certificate authority, issuing the certificate, is compromised then all of the certificates issued by the CA are suspect
  • There may be delays associated with updates to certificates
  • Revoked certificates give the appearance of valid certificates until they are published to a trusted revocation service (OCSP or CRL)
  • The revocation service (OCSP or CRL) may be down during our connection and a browser will need to make a decision will need to be made about trusting the connection
Bare Metal Cyber interpretation

Implementation perspective

Active Certificate Analysis should be treated as a technical defensive capability rather than a product checkbox. In practice, teams should define the protected scope, the conditions under which the technique acts, and the observable evidence that demonstrates the intended behavior. For this technique, likely engineering context includes Certificate File.

Use the technique to identify suspicious, unauthorized, or abnormal activity through observable evidence and repeatable analysis.

Questions to ask

  • Which events, states, or artifacts must be observed for the analysis to work?
  • What analytic logic, threshold, comparison, or signature turns observations into a finding?
  • How are expected false positives, blind spots, and environmental variations documented?
  • Who receives the result, and what action is expected when the technique produces a finding?

Evidence and validation

  • Telemetry and data-source configuration records
  • Analytic logic, thresholds, signatures, and version history
  • Test cases demonstrating expected positive and negative results
  • Alert, triage, escalation, and tuning records

Common failure patterns

  • Required telemetry is missing, delayed, or transformed in a way that invalidates the analysis.
  • The technique produces alerts without an accountable triage and response process.
  • Detection coverage is claimed from product deployment without testing the relevant analytic behavior.

This implementation perspective is original Bare Metal Cyber educational content. It does not replace the official D3FEND definition or establish that a specific product implements the technique.

Ontology hierarchy

Technique hierarchy

Direct child techniques

None listed at this level.

D3FEND graph relationships

Artifacts and ontology entities

These relationships describe how D3FEND connects a defensive technique to artifacts or other ontology entities. They describe graph semantics, not a product certification.

Show inferred artifact relationship paths (1)
Certificate AnalysisanalyzesCertificate File
Inferred and experimental

Offensive-technique relationships

These relationships are generated from D3FEND graph paths and are explicitly experimental. They should be treated as hypotheses for defensive analysis—not as proof that the technique prevents, detects, or removes an offensive behavior.

ATT&CK Enterprise (6)
Source record

Authoritative sources