There are many marketing companies that promote web traffic to different Web pages, software installations, etc. They use what they call  'affiliate programs', paying money for every software installed or traffic generated. This web traffic is very assorted: activex, rogue-antispywares, bundles, banners, fakecodecs, iframes, etc.

Although some of these marketing enterprises can be well-intentioned, other have been specifically created by & for cybercriminals to earn money. Here we can see a gif file that was being used by one of these companies in order to advertise itself in an underground malware forum:

A short time ago, analyzing  a Trj/Sinowal variant (a banking Trojan) to discover where it was sending the information to, it was found one of these websites. It was discovered that this site had 4 different kits to install malware through exploits in the same server the page was hosted in:

There was an IcePack, a Traffic Pro, a Prime Exploit System, and a very basic kit that only used two exploits and had no name. These kits were downloading two Trojans: Trj/Galapoper and Trj/Sinowal. This is not the first time we see something similar. The web sites where they promote themselves use to be very eye-catching, here you can see some examples:

http://fantasticdollars.com/
http://iframe911.com/
http://www.iframebiz.com/
http://loads.cc/

What seems to be the solid theme throughout this whole deal is that most of the Trojan Variants are based on a kit called Mpack.