I'm having this annoying problem: a big ad (named "Recommended for you") that appears on random sites (even here) and remains opened in every tab of all my browsers (Opera, IE).
My OS is Windows 7 Home Premium x64 and i'm using Opera 11.62, IE 9, and did a full scan with MSE. Seems not happening in Firefox. Reinstalling Opera didn't fix the problem.
I can't find how to remove it. I don't even know the name of this. I'll post an image and thanks for helping.
UPDATE: i've changed the image with one from this site. A full scan with Spybot Search & Destroy, Malwayrebte and MSE found nothing.
UPDATE2: found what's the ad is, http://www.bleepingcomputer.com/forums/topic449943.html but my hosts file is clean.