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Smart Spam Filtering For Forums and Blogs?

Posted by timothy on from the world-will-beat-a-path-to-your-door dept.

phorm writes "While filtering for spam on email and other related mediums seems to be fairly productive, there is a growing issue with spam on forums, message-boards, blogs, and other such sites. In many cases, sites use prevention methods such as captchas or question-answer values to try and restrict input to human-only visitors. However, even with such safeguards — and especially with most forms of captcha being cracked fairly often these days — it seems that spammers are becoming an increasing nuisance in this regard. While searching for plugins or extensions to spamassassin etc I have had little luck finding anything not tied into the email framework. Google searches for PHP-based spam filtering tends to come up with mostly commercial and/or more email-related filters. Does anyone know of a good system for filtering spam in general messages? Preferably such a system would be FOSS, and something with a daemon component (accessible by port or socket) to offer quick response-times."

2 of 183 comments (clear)

  1. Second that! by _merlin · · Score: 5, Informative

    Akismet is the best thing for blog spam prevention ever. I can't believe you've never stumbled across it before. It uses statistical analysis to identify spam, and the more people use it, the better it gets. If everyone used it, the blog spammers would just disappear because their attacks would be completely ineffective.

  2. Hidden Input Box by waldoj · · Score: 5, Informative

    Third, do they fill out a hidden inputbox? This is sort of the reverse captcha.

    This is really a very good test. As others have mentioned in this thread, it's the sort of thing that spammers will circumvent if it becomes widespread, but for now it's great.

    There's something else I've found to be really quite effective: deliberately misnaming my form fields. For instance, give the input field that's labelled "First Name" an input name of "phone number." Humans don't use input names to determine what text to enter, but spambots do. Then check that inputâ"if the first name field contains a phone number, you know you've got yourself spammer.

    I've used solely the combination of these two things to run one of my websites for two years now, and I get a vanishingly small amount of spam.