I’m the only administrator with 2 auteur
Do you allow registrations or allow people to subscribe to your site? (Some subscriptions add the users with the role subscriber.)
Check the roles the are given, if its Subscriber, you dont have a problem. As these are people who registered on your site maybe through your Newsletter plugin. But you can choose to delete them at any time. The role of a subscriber is only to leave a comment nothing more.
no it gives them the auteur role like in the picture below
View post on imgur.com
Take a deep breath and carefully follow this guide. When you’re done, you may want to implement some (if not all) of the recommended security measures.
If you’re unable to clean your site(s) successfully, there are reputable organizations that can clean your sites for you. Sucuri and Wordfence are a couple.