Adversaries may modify authentication mechanisms and processes to access user credentials or enable otherwise unwarranted access to accounts. The authentication process is handled by mechanisms, such as the Local Security Authentication Server (LSASS) process and the Security Accounts Manager (SAM) on Windows, pluggable authentication modules (PAM) on Unix-based systems, and authorization plugins on MacOS systems, responsible for gathering, storing, and validating credentials. By modifying an authentication process, an adversary may be able to authenticate to a service or system without using Valid Accounts.
Adversaries may maliciously modify a part of this process to either reveal credentials or bypass authentication mechanisms. Compromised credentials or access may be used to bypass access controls placed on various resources on systems within the network and may even be used for persistent access to remote systems and externally available services, such as VPNs, Outlook Web Access and remote desktop.
| ID | Name | Description |
|---|---|---|
| C0046 | ArcaneDoor |
ArcaneDoor included modification of the AAA process to bypass authentication mechanisms.[1] |
| S0377 | Ebury |
Ebury can intercept private keys using a trojanized |
| G1016 | FIN13 |
FIN13 has replaced legitimate KeePass binaries with trojanized versions to collect passwords from numerous applications.[3] |
| S0487 | Kessel |
Kessel has trojanized the |
| S0692 | SILENTTRINITY |
SILENTTRINITY can create a backdoor in KeePass using a malicious config file and in TortoiseSVN using a registry hook.[5] |
| ID | Mitigation | Description |
|---|---|---|
| M1047 | Audit |
Review authentication logs to ensure that mechanisms such as enforcement of MFA are functioning as intended. Periodically review the hybrid identity solution in use for any discrepancies. For example, review all Pass Through Authentication (PTA) agents in the Azure Management Portal to identify any unwanted or unapproved ones.[6] If ADFS is in use, review DLLs and executable files in the AD FS and Global Assembly Cache directories to ensure that they are signed by Microsoft. Note that in some cases binaries may be catalog-signed, which may cause the file to appear unsigned when viewing file properties.[7] Periodically review for new and unknown network provider DLLs within the Registry ( |
| M1032 | Multi-factor Authentication |
Integrating multi-factor authentication (MFA) as part of organizational policy can greatly reduce the risk of an adversary gaining control of valid credentials that may be used for additional tactics such as initial access, lateral movement, and collecting information. MFA can also be used to restrict access to cloud resources and APIs. |
| M1028 | Operating System Configuration |
Ensure only valid password filters are registered. Filter DLLs must be present in Windows installation directory ( Starting in Windows 11 22H2, the |
| M1027 | Password Policies |
Ensure that |
| M1026 | Privileged Account Management |
Audit domain and local accounts as well as their permission levels routinely to look for situations that could allow an adversary to gain wide access by obtaining credentials of a privileged account. [10] [11] These audits should also include if default accounts have been enabled, or if new local accounts are created that have not be authorized. Follow best practices for design and administration of an enterprise network to limit privileged account use across administrative tiers. [12] Limit access to the root account and prevent users from modifying protected components through proper privilege separation (ex SELinux, grsecurity, AppArmor, etc.) and limiting Privilege Escalation opportunities. Limit on-premises accounts with access to the hybrid identity solution in place. For example, limit Azure AD Global Administrator accounts to only those required, and ensure that these are dedicated cloud-only accounts rather than hybrid ones.[7] |
| M1025 | Privileged Process Integrity |
Enabled features, such as Protected Process Light (PPL), for LSA.[13] |
| M1022 | Restrict File and Directory Permissions |
Restrict write access to the |
| M1024 | Restrict Registry Permissions |
Restrict Registry permissions to disallow the modification of sensitive Registry keys such as |
| M1018 | User Account Management |
Ensure that proper policies are implemented to dictate the the secure enrollment and deactivation of authentication mechanisms, such as MFA, for user accounts. |
| ID | Name | Analytic ID | Analytic Description |
|---|---|---|---|
| DET0104 | Detect Modification of Authentication Processes Across Platforms | AN0287 |
Detects modification of LSASS and authentication DLLs, suspicious registry changes to password filter packages, and abnormal process access to lsass.exe. Correlates registry modifications, DLL loads, and process handle access events. |
| AN0288 |
Detects modification of PAM configuration files, unauthorized new PAM modules, and suspicious process execution accessing PAM-related binaries. Correlates file modification events in /etc/pam.d/ with process execution of unauthorized binaries. |
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| AN0289 |
Detects unauthorized additions or changes to /Library/Security/SecurityAgentPlugins and suspicious process activity attempting to hook authentication APIs. Correlates file modifications with abnormal plugin loads in authentication flows. |
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| AN0290 |
Detects suspicious configuration changes in IdP authentication flows such as enabling reversible password encryption, MFA bypass, or policy weakening. Correlates policy modification events with unusual administrative activity. |
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| AN0291 |
Detects unauthorized changes to IAM authentication configurations such as disabling MFA, creating backdoor access keys, or altering trust policies. Correlates identity policy updates with unusual login behavior. |