Additional Local or Domain Groups
An adversary may add additional local or domain groups to an adversary-controlled account to maintain persistent access to a system or domain. On Windows, accounts may use the net localgroup and net group commands to add existing users to local and domain groups. On Linux, adversaries may use the usermod command for the same purpose.
For example, accounts may be added to the local administrators group on Windows devices to maintain elevated privileges. They may also be added to the Remote Desktop Users group, which allows them to leverage Remote Desktop Protocol to log into the endpoints in the future. Adversaries may also add accounts to VPN user groups to gain future persistence on the network.
On Linux, accounts may be added to the sudoers group, allowing them to persistently leverage Sudo and Sudo Caching for elevated privileges. In Windows environments, machine accounts may also be added to domain groups. This allows the local SYSTEM account to gain privileges on the domain.