I have just noticed 2 authors in my list of 'authors and users', each with Level 10 which means they have full rights. They have no names or nicknames and I can't edit their profiles or even demote them. It may (or may not) be a coincidence that I've just had a new user register with an '@mail.ru' address. I could demote them to a 'user' only but I can do nothing with these anonymous authors and I fear what they might do!
Any suggestions? Yes, I know I should update to a more modern version but I installed WordPress using cPanel and it's consistently failed to upgrade when I try the auto-update routine, despite claiming to do so (as recently as today). I've seen the manual update instructions but as a non-techie, they scare me a lot! I guess I'm going to have to bite that bullet - but I assume I need to remove these guys first.
Any help gratefully received.