The takedown of Mega-D, also known as Ozdok, was spearheaded by researchers at anti-botnet firm FireEye. The botnet comprised tens of thousands of machines and was responsible for sending out a large portion of the spam on the Internetat some points north of 30 percent. Researchers at FireEye then worked with Internet Service Providers (ISPs) to take the servers offline. The company was able to get all but four of the C&C servers offline, and also took six of the domains offline.”]