[Sanlam Cape Town Marathon] New User Registration

Hi team, I loaded the Cerber plugin, hoping it would prevent these fake user registrations on our site. We use a captcha in the registration process, yet these bot registrations come through twice every hour.

This is the typical user reg details, which they automatically alter:

New user registration on your site Sanlam Cape Town Marathon: Username: www.ftjhfh.blogspot.ug - MELSTR0Y 27 991 RUB exha Email: cania230@rambler.ru

I am unable to blacklist a domain as this changes every time. But can I switch to another Cerber setting to stop these registrations?

We use a plugin called Profile Builder to manage registrations, so now all these users are sitting in the “unconfirmed emails” user section. I cannot delete the more than 4000 “users” using the bulk delete as they are still “users.”

Your advise would be appreciated.