T1147

Every user account in macOS has a userID associated with it. When creating a user, you can specify the userID for that account. There is a property value in <code>/Library/Preferences/com.apple.loginwindow</code> called <code>Hide500Users</code> that prevents users with userIDs 500 and lower from appearing at the login screen. By using the [Create Account](https://attack.mitre.org/techniques/T1136) technique with a userID under 500 and enabling this property (setting it to Yes), an adversary can hide their user accounts much more easily: <code>sudo dscl . -create /Users/username UniqueID 401</code> (Citation: Cybereason OSX Pirrit).