In March, this year, Microsoft announced that with the help of industry partners and law enforcement, they had taken down the notorious spamming botnet, Rustock.
Today, the Redmond company made an updated announcement saying that the "Since that time, the botnet has stayed dead."
"Our technical countermeasures have worked effectively to prevent the bot's self-defense mechanisms from reanimating it. Moreover, in the months since the takedown, we've seen the number of infected IP addresses (a loose proxy for the number of infected computers) decline as more and more people update their software or get malware removed from their PCs."
"However, keeping the botnet dead and decaying is just one part of our larger objective. To effectively reduce the global volume of cybercrime, we need to successfully deter the criminals who seek to profit from botnets. To prevent future botherders from hijacking computers to spread malware and come-ons for counterfeit pharmaceuticals, we need to hold today's botherders accountable. As such, the Microsoft Digital Crimes Unit continues to follow this case wherever it leads us. Based on evidence gathered in the case (which can be found at www.noticeofpleadings.com), we’ve reason to believe that the people behind the Rustock botnet either have operated or are operating out of Russia. Consequently, we've placed advertisements in two mainstream Russian newspapers, the Delovoy Petersburg in St. Petersburg and Moscow's daily paper, The Moscow News," stated Richard Boscovich, Senior Attorney, Microsoft Digital Crimes Unit.
"By placing these quarter-page ads, which'll run for 30 days, we honor our legal obligation to make a good faith effort to contact the owners of the IP address and domain names that were shut down when Rustock was taken offline."
[Source Microsoft blog]