The Rustock botnet operated from about 2006 until March of this year. The malware would infiltrate computers when users unwittingly visited compromised websites.
It would cause the infected computer to send out up to 192 spam messages per minute. At its height the botnet is reported to have infected up to 2 million machines worldwide. Rustock was taken down March 16, 2011 after a coordinated effort between Microsoft, Federal law enforcement agents, University of Washington and FireEye a computer security company, 97 of botnets US-based command and control servers were seized in the operation.
Microsoft believes the Rustock operators reside in Russia in the city of St. Petersburg or Moscow. Richard Boscovic, senior attorney for the Microsoft Digital Crimes Unit, explained in a blog post that the $250,000 reward “stems from Microsoft’s recognition that the Rustock botnet is responsible for a number of criminal activities and serves to underscore our commitment to tracking down those behind it. “While the primary goal for our legal and technical operation has been to stop and disrupt the threat that Rustock has posed for everyone affected by it, we also believe the Rustock bot-herders should be held accountable for their actions.
“Before this reward offer, Microsoft had posted rewards for the makers of the Blaster, Sobig, MyDoom and Conficker worms. Those rewards have gone unclaimed. Anyone with information about individuals responsible for Rustock can email Microsoft at: email@example.com