Microsoft announced Thursday that it won its civil case against the Rustock operators six months after it successfully took down the botnet. The software giant will now hand all of the evidence it gathered during this time to the FBI, which could pursue a possible criminal case.
This outcome is exactly what Microsoft had hoped for: that those responsible for operating the Rustock botnet will be held accountable for their actions.
"We have successfully concluded our civil case against the Rustock botnet operators," Microsoft Senior Attorney Richard Domingues Boscovich wrote in a blog post describing the action. "This case not only enabled the takedown of a botnet known to be one of the single largest sources of spam on the Internet, but it is now helping to ensure that this botnet will never be used for cybercrime again."
Microsoft's Digital Crimes Unit (DCU) shut down Rustock back in March, following an earlier success against another botnet called Waledac. Rustock was estimated to have infected more than a million PCs at the time of its takedown and was sending billions of spam emails every day.
Microsoft offered a $250,000 reward for information leading to the arrest and conviction of Rustock's operators back in July. That reward will remain in effect, though tips should be now sent directly to the FBI instead of to the company as before.
Microsoft has also created a video describing its takedown of the Rustock botnet.