Since a couple of weeks people using WP Mollom got hit by some spam. On friday, Bert took the problem to Twitter, which caught my attention. Of course, we want to get rid of all the spam and so I notified Dries.

Over the weekend, Dries did some research in the logfiles and noticed some disturbing patterns concerning feedback sent from WordPress blogs using the plugin. Most moderated messages got reported as ‘profanity’ rather then ‘spam’. That led, with the much appreciated help of Pascal, to the discovery of a nasty bug in the feedback functions of the plugin.

It seems that spam was reported as ‘profanity’ and ‘unwanted’ as ‘spam’. The feedback qualifiers got totally messed up in a conditional block… and accustomed with the code as I got, I probably read over it a thousand times without really noticing the error. Through sending the wrong qualifiers, the Mollom servers can not interpret correctly what is spam or not for your blog. This has, of couse, a serious impact on the performance of Mollom.

Given the nature and the severity of the error, I corrected it and put version 0.6.2 with *only* this bugfix up for release on WordPress Extend. So, if you’re running version 0.6.1 or lower, you should download the fixed version as soon as possible.