Microsoft’s Kelihos botnet suspect used to work for computer security firm

Graham Cluley
Graham Cluley
@[email protected]

Andrey Sabelnikov's LinkedIn photographMicrosoft has named a 31-year-old Russian, who used to work at a firm producing anti-virus and firewall software, believing him to be responsible for attacks perpetrated by the Kelihos botnet.

Andrey Sabelnikov, of St Petersburg, Russia, has been named in an amended complaint filed by the software giant with the US District Court.

Microsoft says it believes that Sabelnikov created the Kelihos malware, and alleges that he “used the malware to control, operate, maintain and grow the Kelihos botnet”.

Furthermore, Microsoft alleges that Sabelnikov registered 3,723 “” website subdomains, and misused those subdomains to operate and control the Kelihos botnet for the purposes of sending spam.

Sign up to our free newsletter.
Security news, advice, and tips.

Diagram of Kelihos botnet

What is perhaps most surprising is Sabelnikov’s background. According to his public LinkedIn profile, from 2005-2007 he was a senior developer and product manager at Agnitum, a Russian security firm well-known for its firewall software.

There is no suggestion that Agnitum are connected with the allegations, or that their security software – which includes anti-virus products – are compromised in any way.

Microsoft, working with the computer security industry, neutralised the Kelihos botnet in September 2011. Despite that Richard Boscovich, senior attorney for Microsoft’s Digital Crimes Unit, says that thousands of computers remain infected and that the case “is not over.”

A settlement was agreed last year between Microsoft and Dominique Piatti and his company dotFREE Group, which owned, giving Microsoft control of the subdomains.

That also had the positive side effect of taking a number of websites offline that had been distributing the MacDefender family of malware which plagued Mac users last year.

Graham Cluley is an award-winning keynote speaker who has given presentations around the world about cybersecurity, hackers, and online privacy. A veteran of the computer security industry since the early 1990s, he wrote the first ever version of Dr Solomon's Anti-Virus Toolkit for Windows, makes regular media appearances, and is the co-host of the popular "Smashing Security" podcast. Follow him on Twitter, Mastodon, Threads, Bluesky, or drop him an email.

What do you think? Leave a comment

Your email address will not be published. Required fields are marked *

This site uses Akismet to reduce spam. Learn how your comment data is processed.