A group of hackers from Estonia and Russia have been charged with 27 counts of conspiracy and wire fraud, following an FBI-led investigation into a botnet found by NASA computer scientists two years ago. The underlying malware was found to have infected more than four million computers worldwide, creating a botnet where adverts and web searches were replaced with pages which generated ad revenue for the hackers — a clickjacking scheme that ran for four years and generated an estimated $14m.

The attorney who unsealed the case earlier today told Bloomberg that he believed that this case is the first of its kind, specifically calling out the large scale as being highly unusual. He also added that the servers based in New York and Chicago responsible for delivering ads to infected systems were only disabled early yesterday morning. With the six Estonian citizens behind the virus now facing extradition to the US (their Russian associate is yet to be caught), we're sure that we'll hear more on this very soon.

Update: The FBI has issued instructions on how to check if your computer's infected, and how to clean up anything you find.

Image credit: Flickr / .hj baraza