Microsoft used a combination of technical and legal manuevers to effectively shut down the Rustock botnet earlier this year. Just because the ongoing threat has been stifled doesn’t mean Microsoft is done pursuing it, though.
A post on the Microsoft Privacy and Safety blog states:
Today, we take our pursuit a step further. After publishing notices in two Russian newspapers last month to notify the Rustock operators of the civil lawsuit, we decided to augment our civil discovery efforts to identify those responsible for controlling the notorious Rustock botnet by issuing a monetary reward in the amount of $250,000 for new information that results in the identification, arrest and criminal conviction of such individual(s).
For more details on the ongoing efforts and Microsoft’s reward for Rustock information, click here.