Receiving a CSS hack warning, what does that mean?

Antispam bee is hiding the original comment form and is using a more secure own form. If the hidden comment form is filled out, this can’t be a human and have to be bot (because this method is using CSS for hiding the form it is called “CSS hack”).

Comment spam with spam reason “CSS hack” are 99,999999% spam.

Does this help you?

All the best,
Torsten

Thank you. Yes it helped tremendously Torsten, now I know what that means. I had been looking everywhere for an answer but couldn’t find anything to help. The WP support board sent me over here to you.

I understand what a bot is but how does a bot write a comment? that I do not understand.

@martij715 So a bot in this case essentially would be a script/program that crawls the internet in order to find comment forms to post spam through. (Please don’t ask for technical background on how exactly a script would actually “crawl”–in this example it just does. ;))
The script would find the comment form of any post on your site and submit whatever it has been programed to submit—that’s essentially (and enormously simplified) how comment spam works.
Antispam Bee would recognize said programatically submitted comment as spam for you by applying various checks one of which is called the “CSS hack”.