The Rustock “botnet” consisted of about a million computers that were infected with malicious code to let hackers covertly control the machines from afar using “command and control” servers.<\/p>\n
Owners of infected computers are typically not aware that hackers are using their machines.<\/p>\n
“Bot-herders infect computers with malware in a number of ways, such as when a computer owner visits a website booby-trapped with malware and clicks on a malicious advertisement or opens an infected email attachment,” said Microsoft Digital Crimes Unit senior attorney Richard Boscovich.<\/p>\n
“Bot-herders do this so discretely that owners often never suspect their PC (personal computer) is living a double life.”<\/p>\n
Rustock was reported to be among the world’s largest spam botnets and was capable of sending as many as 30 billion emails per day.<\/p>\n
Much of the email sent by Rustock advertised counterfeit or unapproved knock-off versions of drugs like Viagra, while other spam tried to dupe people with bogus Microsoft lottery notices, according to Boscovich.<\/p>\n
Microsoft worked with Viagra-maker Pfizer and network security firm FireEye during a months-long investigation that culminated with using US warrants to seize “command and control” servers in the western state of Washington.<\/p>\n
Rustock was knocked offline on Wednesday when the connection was severed between infected computers and the machines used to give them orders, according to Boscovich.<\/p>\n
Evidence seized was being analyzed for clues about the hackers and their operations. Microsoft was offering tools at support.microsoft.com\/botnets to purge the malware from infected computers.<\/p>\n