Spam Filter for Forum

[K.I.L.E.R]

I just added a new spam-divert-countermeasure.

Actually, the first countermeasures implemented on the temple were far too naive: they relied on JS validation, easily overrideable by the experienced spambot.

This time, it's different 

You used server side validation?

[Darren Grey]

Reviving the spam topic, I noticed this user online today:

http://roguetemple.com/forums/index.php?action=profile;u=1507

Looking at the profile it's clearly a spambot.  Looking at the members list of people with zero posts and links in their profiles... there seems to be several hundred of these.  Note that they can access e-mail addresses of forum members, increase server traffic, upset Google analytics of the site, whilst also being a general nuisance on the web by hijacking your site to increase the owners' search rankings.  This isn't a problem to be ignored - the ADOM forums have recently been closed to new members due to several thousand of these sorts of bots signing up.

I don't know what spam protection is currently in place, but none are perfect and there needs to be some regular clean-up operations.  Options:

1. Delete all zero posts accounts older than a month, every month.
2. Manually look through every zero posts account to look for links on their profile, and delete obvious spambots.

1 is easyish, but a bit unfair on lurkers.  Still, all they'd have to do to remain lurkers is make 1 legitimate post.  2 is difficult, but if performed monthly isn't too much of a chore.  I'm sure many forum members would be happy to help flag up these sorts of accounts.

[Serial Kicked]

There's several solutions to deal with spam bots.

- Using ReCaptcha for user registration is usually enough to get rid of 90% (or more) of the spam bots. Very few pass this kind of protection. Usually only those using 'paid' people in poor countries instead of algorithms are successful here. 

- Black list well known spam related IP ranges.

- Forbid users with less than X post to post links on the board.

- Most forum and website systems have relatively well working anti-spam plugins. I'm using Akismet myself on some of my websites and so far it has been 100% successful. I'm pretty sure they have a plugin for SMF too.