Fighting SPAM in phpBB

At tag2find, we are using phpBB2+ for our forum. This forum unfortunately is continuously being spammed by bots, despite the active CAPTCHA. Even at the strongest setting of the CAPTCHA, SPAM postings were coming through, but the CAPTCHA drove off a lot of potential forum posters which could not get past it.

Therefore I wanted to implement the approach I took for our blog: disable the possibility to submit postings containing links. Unfortunately phpBB out of the box does not permit this. After searching a while I found a promising MOD which I now added to the forum. Its not directly preventing posting links, but is more or less a RegEx-based blacklist of words which must not be used by users who are not registered for a certain number of days and have not yet posted a certain number of posts. The regular expressions supplied aim at preventing posting links, but I had to modify them, as they also contain “.net” which we must allow since our application is written in the Microsoft .NET Framework, so this term is going to turn up legitimately.

Let’s see if this measure will actually change the amount of SPAM being posted to the forum.