For connecting to services (such as WinRM), it’s often possible to manipulate the service ACL rather than the user’s privileges. For example, adding a user to the Microsoft.PowerShell
security descriptor with the “Full Control” permission will enable access to the WinRM service, regardless of the permissions explicitly assigned to the user.
The advantage to manipulating user privileges and service ACLs directly is that it’s less obvious that a user is back-doored.