MyBB Community Forums

Hello! On my forum recorded many spammers do that? How do I fight with them?

Try using a security question instead of captcha, and when asking the question try making the user copy and a paste the text. In example:

Q: Use this as the answer "g2b#n$!g"
A: g2b#n$!g

Using a method such as that, you won't have any spambots that are able to make it through (only human spambots). It's a tried and true method that I've used on multiple forums now without dealing with any spambots being able to sign up, and then one who do still don't post anything.

edit: delayed response

you can use stop forum spam plugin, strong questions for signup & also put posts by new members in moderation
(MyBB 1.6 version plugin -> required approvals)