Microsoft Corp. has announced that its joint effort with United States federal authorities were able to take down one of the biggest producers of spam e-mail.

The company has said its legal action against the operator of the Rustock "botnet," which consists of a network of infected computers programmed to send junk e-mail, has resulted to raids across the country last week aiming to shut down networks.

The Rustock network has been estimated by tech security bloggers as responsible for over half of the spam appearing in our e-mail's inbox. The raids, as observed by these bloggers, has caused a sharp dip in spam e-mails, although total eradication could take years.

Before the raids, Microsoft got permission from federal court in Seattle, where the company had filed a lawsuit against the botnet's operators. The company also said it collaborated with U.S. Marshals Service to raid hosting providers in seven cities in the country, including Denver, Dallas, Chicago, Seattle, and Columbus.

Microsoft estimates that there are as much as 1 million computers that are infected with the Rustock malware, which sends out as much as 30 billion spam e-mails every day without the users knowing about it. This malware is usually downloaded onto PCs through an advertisement on a website.

Source: Globe and Mail