Microsoft has now issued a statement denying previous media reports that the Kelihos botnet is back in operation, although it did say a new malware variant seems to be on the rise.
A week of Windows 10, holograms and Exploding Kittens on Mars
Office 2016 launching this year, touch apps coming soon
Microsoft reveals the next version of Windows 10
Introducing Windows 10 for phones
Hands on with HoloLens
Download: Windows 10 build 9926
The Kelibos botnet, an infected network of PCs that Microsoft said it helped to shut down in September 2011, may be making a comeback due to its unknown creators taking control again.
The newly revealed suspect in the Kelihos botnet case, Andrey Sabelnikov, has denied any involvement in the creation of the botnet despite statements by Microsoft to the contrary.
Microsoft has announced that it has helped to not only shut down the Kelihos botnet but has also named a person, Dominique Alexander Piatti, as an defendant in the case.