Today, Microsoft's Digital Crimes Unit announced that we have concluded our civil case against the Rustock botnet operators and turned evidence found during that investigation over to the FBI as a criminal referral. While the FBI will be driving that investigation, we will continue to offer the $250,000 reward for information which leads to the arrest and conviction of Rustock's operators. Any leads can be sent to ms_referrals@ic.fbi.gov.

We will continue to work with ISPs and CERTs to clean infected computers utilizing the telemetry we receive from having control of Rustock's command and control domains. Since the takedown in March, and through this cooperation, the Rustock botnet has declined in volume by almost 75%. You can see more about the overall volume at peak in the special edition of our Security Intelligence Report on Rustock which we released in June.
 
If you believe you may have a computer under your control which is infected with Rustock, you can find support information here: http://support.microsoft.com/contactus/cu_sc_virsec_b107#tab0
 
It is our recommendation that any system infected with Rustock be cleaned with a full antivirus product as our telemetry shows that machines infected with Rustock are generally infected with other malicious software as well.
 
-- MMPC, Jeff Williams