Adversaries may manipulate accounts to maintain access to victim systems. Account manipulation may consist of any action that preserves adversary access to a compromised account, such as modifying credentials, machine identities or permission groups.
These actions could also include account activity designed to subvert security policies, such as performing iterative password updates to bypass password duration policies and preserve the life of compromised credentials. In order to create or manipulate accounts, the adversary must already have sufficient permissions on systems or the domain.
The Mimikatz credential dumper has been extended to include Skeleton Key domain controller authentication bypass functionality. The
This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.
Collect events that correlate with changes to account objects and/or permissions on systems and the domain, such as event IDs 4738, 4728 and 4670. Monitor for modification of accounts in correlation with other suspicious activity. Changes may occur at unusual times or from unusual systems. Especially flag events where the subject and target accounts differ or that include additional flags such as changing a password without knowledge of the old password.
Monitor for use of credentials at unusual times or to unusual systems or services. This may also correlate with other suspicious activity.
Monitor for unusual permissions changes that may indicate excessively broad permissions being granted to compromised accounts.
- MITRE ATT&CK
- Metcalf, S. (2015, November 13). Unofficial Guide to Mimikatz & Command Reference. Retrieved December 23, 2015.
- Metcalf, S. (2015, January 19). Attackers Can Now Use Mimikatz to Implant Skeleton Key on Domain Controllers & BackDoor Your Active Directory Forest. Retrieved February 3, 2015.
- Lich, B., Miroshnikov, A. (2017, April 5). 4738(S): A user account was changed. Retrieved June 30, 2017.
- Franklin Smith, R. (n.d.). Windows Security Log Event ID 4670. Retrieved November 4, 2019.
- Warren, J. (2017, July 11). Manipulating User Passwords with Mimikatz. Retrieved December 4, 2017.
- Warren, J. (2017, June 22). lsadump::changentlm and lsadump::setntlm work, but generate Windows events #92. Retrieved December 4, 2017.