Steal or Forge Authentication Certificates

Executive Summary

Steal or Forge Authentication Certificates (T1649) is a MITRE ATT&CK technique associated with Credential Access. Adversaries may steal or forge certificates used for authentication to access remote systems or resources.

Why Attackers Use It

Attackers use Steal or Forge Authentication Certificates because it provides a reliable way to advance their objective within the Credential Access tactic, often with a favorable balance of impact versus detectability on Windows, Linux, macOS, Identity Provider environments. Defenders should assess this behavior in the context of the affected platform and adjacent activity rather than treating it as a standalone indicator.

MITRE Description

Adversaries may steal or forge certificates used for authentication to access remote systems or resources. Digital certificates are often used to sign and encrypt messages and/or files. Certificates are also used as authentication material. For example, Entra ID device certificates and Active Directory Certificate Services (AD CS) certificates bind to an identity and can be used as credentials for domain accounts.(Citation: O365 Blog Azure AD Device IDs)(Citation: Microsoft AD CS Overview)

Authentication certificates can be both stolen and forged. For example, AD CS certificates can be stolen from encrypted storage (in the Registry or files)(Citation: APT29 Deep Look at Credential Roaming), misplaced certificate files (i.e. Unsecured Credentials), or directly from the Windows certificate store via various crypto APIs.(Citation: SpecterOps Certified Pre Owned)(Citation: GitHub CertStealer)(Citation: GitHub GhostPack Certificates) With appropriate enrollment rights, users and/or machines within a domain can also request and/or manually renew certificates from enterprise certificate authorities (CA). This enrollment process defines various settings and permissions associated with the certificate. Of note, the certificate’s extended key usage (EKU) values define signing, encryption, and authentication use cases, while the certificate’s subject alternative name (SAN) values define the certificate owner’s alternate names.(Citation: Medium Certified Pre Owned)

Abusing certificates for authentication credentials may enable other behaviors such as Lateral Movement. Certificate-related misconfigurations may also enable opportunities for Privilege Escalation, by way of allowing users to impersonate or assume privileged accounts or permissions via the identities (SANs) associated with a certificate. These abuses may also enable Persistence via stealing or forging certificates that can be used as Valid Accounts for the duration of the certificate's validity, despite user password resets. Authentication certificates can also be stolen and forged for machine accounts.

Adversaries who have access to root (or subordinate) CA certificate private keys (or mechanisms protecting/managing these keys) may also establish Persistence by forging arbitrary authentication certificates for the victim domain (known as “golden” certificates).(Citation: Medium Certified Pre Owned) Adversaries may also target certificates and related services in order to access other forms of credentials, such as Golden Ticket ticket-granting tickets (TGT) or NTLM plaintext.(Citation: Medium Certified Pre Owned)

Attack Flow

1. Attacker gains the prerequisite access or context described below.
2. Attacker executes Steal or Forge Authentication Certificates to achieve its tactical objective (Credential Access).
3. Resulting access/data/effect is leveraged to advance the broader attack chain (see Related Techniques).

Prerequisites

• Platform(s): Windows, Linux, macOS, Identity Provider
• ATT&CK does not define one universal permission requirement for this technique. Establish the required access from the observed implementation and affected platform.

Common Tools

• Tool attribution is implementation-specific. Use ATT&CK procedure examples and local telemetry to identify the binaries, services, scripts, accounts, or cloud resources involved.

Commands

No universal command represents Steal or Forge Authentication Certificates. Capture the exact command line, arguments, parent process, account, host, and execution time from the investigated environment; do not operationalize unverified examples.

Network Traffic

• Network observability is implementation-dependent. Review DNS, proxy, firewall, flow, authentication, and packet telemetry around the activity window, then correlate remote endpoints and protocol behavior with host evidence.

Windows Events

Sysmon Events

Detection Opportunities

No MITRE detection guidance published for this technique.

Relevant ATT&CK Data Sources: N/A

Sigma Rules

A universal Sigma rule would create unreliable results because this technique has no single guaranteed observable. Build detection logic from a documented behavior and supported data source, scope it to the affected platform, and validate it against benign administrative activity before deployment.

Splunk Queries

Start with the data sources named in the detection section. Scope searches by asset, identity, and time window; correlate the primary behavior with preceding access and subsequent actions. A portable query is intentionally not provided where the technique lacks a universal schema or observable.

Investigation Workflow

1. Confirm that the observed behavior is consistent with Steal or Forge Authentication Certificates and rule out expected administrative or application activity.
2. Establish the first-seen time, initiating identity, source system, target system, and affected resources.
3. Collect relevant host, identity, network, cloud, and application telemetry for the surrounding time window.
4. Correlate parent and child activity, remote connections, file or configuration changes, and related ATT&CK techniques.
5. Determine scope by searching for the same observable across peer assets and identities.
6. Preserve volatile evidence and record confidence, assumptions, and telemetry gaps before containment.

Containment

1. Isolate affected host(s)/account(s) identified during investigation.
2. Revoke or rotate any credentials/tokens potentially exposed.
3. Apply the mitigations listed below where not already enforced.
4. Validate no related techniques (see Related Techniques) were chained against the same asset.

Mitigation

• M1015 -- Active Directory Configuration: Implement robust Active Directory (AD) configurations using group policies to secure user accounts, control access, and minimize the attack surface.
• M1042 -- Disable or Remove Feature or Program: Disable or remove unnecessary and potentially vulnerable software, features, or services to reduce the attack surface and prevent abuse by adversaries.
• M1041 -- Encrypt Sensitive Information: Protect sensitive information at rest, in transit, and during processing by using strong encryption algorithms.
• M1047 -- Audit: Auditing is the process of recording activity and systematically reviewing and analyzing the activity and system configurations.

Related Techniques

• T1003.004
• T1552.004
• T1558.002