CyberStack

MITRE ATT&CK / Techniques / T1556.001

Modify Authentication Process: Domain Controller Authentication

ID
T1556.001
Tactics
TA0003 Persistence, TA0006 Credential Access, TA0112 Defense Impairment
Sub-technique of
T1556 Modify Authentication Process
Platforms
Windows
Data sources
Process Access, Module Load, Logon Session Creation, File Modification
Source
attack.mitre.org
MITRE last modified
12 May 2026

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). Skeleton key works through a patch on an enterprise domain controller authentication process (LSASS) with credentials that adversaries may use to bypass the standard authentication system. Once patched, an adversary can use the injected password to successfully authenticate as any domain user account (until the the skeleton key is erased from memory by a reboot of the domain controller). Authenticated access may enable unfettered access to hosts and/or resources within single-factor authentication environments.[5]

Detection

Mitigations (4)

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.[1]

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. [2] [3] 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. [4]

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.

Groups (1)

Software (1)

References

  1. Microsoft LSA
  2. TechNet Credential Theft
  3. TechNet Least Privilege
  4. Microsoft Securing Privileged Access
  5. Dell Skeleton