Query: explain T1649 Steal or Forge Authentication Certificates
Matching passage: T1649 Steal or Forge Authentication Certificates. Tactics: credential access. 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](https://attack.mitre.org/techniques/T1552)), 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](https://attack.mitre.org/tactics/TA0008). Certificate-related misconfigurations may also enable opportunities for [Privilege Escalation](https://attack.mitre.org/tactics/TA0004), 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](https:/
Near-miss passage: T1556.003 Pluggable Authentication Modules. Tactics: defense impairment, persistence, credential access. Description: Adversaries may modify pluggable authentication modules (PAM) to access user credentials or enable otherwise unwarranted access to accounts. PAM is a modular system of configuration files, libraries, and executable files which guide authentication for many services. The most common authentication module is <code>pam_unix.so</code>, which retrieves, sets, and verifies account authentication information in <code>/etc/passwd</code> and <code>/etc/shadow</code>.(Citation: Apple PAM)(Citation: Man Pam_Unix)(Citation: Red Hat PAM) Adversaries may modify components of the PAM system to create backdoors. PAM components, such as <code>pam_unix.so</code>, can be patched to accept arbitrary adversary supplied values as legitimate credentials.(Citation: PAM Backdoor) Malicious modifications to the PAM system may also be abused to steal credentials. Adversaries may infect PAM resources with code to harvest user credentials, since the values exchanged with PAM components may be plain-text since PAM does not store passwords.(Citation: PAM Creds)(Citation: Apple PAM)