We'll create fresh WordPress site with WordPress Protect Admin installed. You have 20 minutes to test the plugin after that site we'll be deleted.
Protect WordPress Admin is a plugin that helps wordpress administrators to hide wp-admin and wp-login pages from non-logged in users. The result is that in case of brute force attacks, the protected login pages will return 404 error.
In order to access the admin area, the users will have to go to wp-login page which in turn requires some authorization key and values passed as parameters to wp-login.php. Then only login page is available. In all the other cases, only 404 page is shown.