T1556.001sub-technique of T1556 Modify Authentication Process
Domain Controller Authentication
Windowsnothing on this site yetT1556.001 on attack.mitre.org
Adversaries may patch the authentication process on a domain controller to bypass the typical authentication mechanisms and enable access to accounts. Malware may be used to inject false credentials into the authentication process on a domain controller with the intent of creating a backdoor used to access any user’s account and/or credentials (ex: Skeleton Key).
If this is happening now
Checklists and playbooks to open while the alert is still live.
Suspicious execution on an endpoint
An EDR alert, an unexplained process, or a user reporting something odd.
Ransomware, suspected or confirmed
Files renamed or unreadable, a ransom note, or backup deletion commands seen.
Cloud account compromise
Impossible travel, an unrecognised inbox rule, or a reported invoice-fraud attempt.
how MITRE says to see it
Detect Domain Controller Authentication Process Modification (Skeleton Key)
- Detects anomalous process access to LSASS on domain controllers, suspicious module loads of authentication DLLs, and registry or file modifications indicative of Skeleton Key–style patching. Correlates LSASS access attempts with subsequent abnormal logon activity patterns.
what reduces it
- M1017 User Training. Train users to recognize and handle suspicious email attachments. Emphasize the importance of caution when opening attachments from unknown or unexpected sources, even if they appear legitimate. Implement email warning banners to alert users about emails originating from outside the organization or containing attachments, reinforcing awareness and helping users identify potential spearphishing attempts.
- M1025 Privileged Process Integrity. Enabled features, such as Protected Process Light (PPL), for LSA.
- 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. These audits should also include if default accounts have been enabled, or if new local accounts are created that have not be authorized.
- 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.