monkeybusiness

Trying to log into a site , nay not have been on it before, but these usernames pop up for signing in I already know they are the wrong ones and don't even belong to that site as sign in., I never used them and the email either, how do I turn this off or delete them, they're NOT even for the site I'm trying to log into. It also does it to other sites too, not the correct logins either, want to delete them