London: The world`s most prolific source of spam e-mails -- an international network of virus-infected computers -- has been shut down in a series of coordinated raids by Microsoft and US federal authorities.
The Rustock botnet had for years generated billions of e-mails per day, promoting unlicensed online pharmacies and cut-price anti-impotence pills. A botnet is a collection of software agents that run autonomously and automatically.
But early last week, security firms noticed that e-mail traffic from Rustock completely collapsed, the Telegraph reports.
The scale of the shutdown is unprecedented. A report last month by SecureWorks, a computer security firm, said Rustock was the world`s biggest source of spam.
It has now been revealed that Microsoft, backed by US marshals acting on a court order, seized servers that it`s estimated covertly controlled almost a million Windows PCs.
"We think this has been 100 percent effective," said Richard Boscovich, senior attorney at Microsoft`s digital crimes unit.
The criminals behind the spamming business were named in Microsoft`s lawsuit only as "John Does 1-11".
To get the court order, which empowered it to seize equipment and so "decapitate" the botnet, Microsoft alleged the "John Does" infringed its trademarks in some of their e-mails.
"The reasons for this are due to the author`s relentless development of stealth tactics," it said, referring to how Rustock was frequently updated to stay one step ahead of anti-virus packages.