Account Access Removal

Adversaries may interrupt availability of system and network resources by inhibiting access to accounts utilized by legitimate users. Accounts may be deleted, locked, or manipulated (ex: changed credentials) to remove access to accounts.

Adversaries may also subsequently log off and/or reboot boxes to set malicious changes into place.[1][2]

ID: T1531
Tactic: Impact
Platform: Linux, macOS, Windows
Permissions Required: User, Administrator, root, SYSTEM
Data Sources: Windows event logs, Process command-line parameters, Process monitoring
Impact Type: Availability
Version: 1.0

Procedure Examples

Name Description
LockerGoga LockerGoga has been observed changing account passwords and logging off current users. [1] [2]

Mitigations

This type of attack technique cannot be easily mitigated with preventive controls since it is based on the abuse of system features.

Detection

Use process monitoring to monitor the execution and command line parameters of binaries involved in deleting accounts or changing passwords, such as use of Net. Windows event logs may also designate activity associated with an adversary's attempt to remove access to an account:

  • Event ID 4723 - An attempt was made to change an account's password
  • Event ID 4724 - An attempt was made to reset an account's password
  • Event ID 4726 - A user account was deleted
  • Event ID 4740 - A user account was locked out

Alerting on Net and these Event IDs may generate a high degree of false positives, so compare against baseline knowledge for how systems are typically used and correlate modification events with other indications of malicious activity where possible.

References