We have encountered additional administrator accounts on clients websites that no one seems to have created or can account for. As part of a WordPress Security Maintenance check the following needs to be done, at minimum:
- Remove all unaccounted for admin accounts – restrict it to one or two
 - If feasible whitelist yours and the clients static IPs
 - Change the default path to the admin panel
 - Maintain an access log of all logins to the admin panel.
 - Blacklist IPs that repeatedly attempt to gain unauthorised access.
 - Enforce a strong password policy
 - Add Two Factor authentication
 
