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 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
Use multi-factor authentication for user and privileged accounts.
Configure access controls and firewalls to limit access to critical systems and domain controllers. Most cloud environments support separate virtual private cloud (VPC) instances that enable further segmentation of cloud systems.
|Operating System Configuration||
Protect domain controllers by ensuring proper security configuration for critical servers to limit access by potentially unnecessary protocols and services, such as SMB file sharing.
|Privileged Account Management||
Do not allow domain administrator accounts to be used for day-to-day operations that may expose them to potential adversaries on unprivileged systems.
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.
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- US-CERT. (2018, March 16). Alert (TA18-074A): Russian Government Cyber Activity Targeting Energy and Other Critical Infrastructure Sectors. Retrieved June 6, 2018.
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- 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.
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