|As one article cites a report by Symantec which shows that the volume of spam has decreased by 90% over the past year, from 225 billion emails a day to 25 billion, and certainly much of this can be accredited to corporate and governmental action. Even so, the botnet business is lucrative one.
The Rustock botnet was taken down this March after running 5 years in Operation b107 executed by Microsoft, FireEye, Pfizer, University of Washington, and federal agents. It had infected some 2 million Windows machines each able to send 30 billion emails a day. Yet, there are others like Rustock which implement rootkit technology, namely, the TDSS.