How to deal with spammers?

Question

phpBB

The forum was attacked by spammers. https://www.programmatron.comHow to deal with it?

Answer 1

For me, the forum itself looks like some kind of spam - thousands of empty categories, among which 2-3 are active.
As for spam bots, it's better to put some kind of recaptcha instead of a simple arithmetic example that only a lazy bot can't figure out.
Plus, perhaps, pre-moderation for new users (after 2-3 approved messages, remove from the group of moderated ones, PHPBB has such functionality out of the box).