JS_Harris - 7:46 am on Dec 8, 2008 (gmt 0)

Theres a particularly nasty virus making the rounds as I write this that doesn't do anything to your computer or websites but it swaps out the ads on sites you visit. You "think" you're seeing the site as intended but the advertising doesn't belong to that site.

How are you supposed to know? The code is well hidden and launches in the background with IE. It does NOT launch with firefox but if it has been launched already it will replace ads on firefox too.

The best way to test for this, because there really is no other trace of it (yes, it's that fast and smooth and kills cookies etc) is to visit your yahoo email and hover over an ad momentarily. If your computer is infected the ad will show in the nav bar as being served by a third party server, not by yahoo. The ads are high quality from various sources (except for the "get free icons" ad that Yahoo would never show).

This type of infection steals website owners money without touching their sites and without doing anything nasty to your computer.