Information
This policy setting prevents connected users from being enumerated on domain-joined computers.
The recommended state for this setting is: Enabled.
Rationale:
A malicious user could use this feature to gather account names of other users, that information could then be used in conjunction with other types of attacks such as guessing passwords or social engineering. The value of this countermeasure is small because a user with domain credentials could gather the same account information using other methods.
Solution
To establish the recommended configuration via GP, set the following UI path to Enabled:
Computer Configuration\Policies\Administrative Templates\System\Logon\Do not enumerate connected users on domain-joined computers
Impact:
The Logon UI will not enumerate any connected users on domain-joined computers.
Default Value:
Disabled. (Connected users will be enumerated on domain-joined computers.)