Joomla and WordPress sites' administrators should consider updating to the latest version of their respective content management system as soon as possible since, according to reports, malware peddlers are bent on compromising them with "some tool that's basically firing a bunch of Joomla and Wordpress exploits at a given server and hoping something hits."

The compromised websites are then embedded with an iFrame that first directs users to a traffic distribution system, and then to a page hosting an exploit kit.

In the end, users who are vulnerable to some of the exploits served by the kit get served with fake AV solutions that show alarming scanning result and urge them to "buy" the rogue solution in order to keep themselves safe.

According to The H, the criminals behind this scheme are not only earning money from the sales of the fake AV, but also from buying and selling web traffic via the aforementioned traffic distribution system.

"Right now it seems the biggest pain is around Joomla users, particularly with extensions which greatly increase the vulnerability footprint and the one thing helping WordPress is the really nice feature of 1-button upgrades (and upgrades which don't tend to break your website)," points out John Bambenek over at SANS' ISC Diary blog.

Administrators that have not kept their CMSs updated might want to check their JavaScripts for suspicious iFrames.