Microsoft: Kelihos botnet still down, new one emerging

Old Kelihos remains on 10,000 computers

Microsoft says the 41,000-strong Kelihos botnet it knocked out last year is still out of action, but clarified a new one is being developed using similar code.

Microsoft issued a statement last Friday clarifying confusion after Kaspersky Lab published a report, which noted the limitations to ending a botnet's life by disrupting and seizing its command infrastructure, as Microsoft, Kaspersky and Kyrus Tech had last September.

Commenting on the emergence of the emergence of a Kelihos bot, Kaspersky Lab researcher Maria Garnaeva wrote that its role in the take down, which focussed on "sinkholing" the botnet's traffic after its domain names were seized, was good at disrupting an operation but not effective if the bot masters were still at large.

Microsoft may have found at least one of the people in such a position after naming Russian software developer Andrey Sabelnikov as the maker of Kelihos -- an allegation he has denied and says he will fight.

Garnaeva also said it was "impossible to neutralise a botnet by taking control over the controller machines or substituting the controller list without any additional actions" since a botnet master could, if they knew the list of active router IPs, regain control of the network with a bot update.

Microsoft's Digital Crimes Unit senior attorney Richard Boscovich confirmed it had evidence of a new botnet, consisting of very similar code to the old Kelihos.

However, he added that "this does not mean that the Kelihos botnet we took down is back in operation, but that a new version of Kelihos malware known as ‘Backdoor: Wion32/Kelihos.B’ is being used to create a new botnet."

Since the take down of the first Kelihos botnet, Microsoft's Malicious Software Removal Tool (MSRT) -- which removes "actively running" viruses, worms and Trojans, but not dormant malware -- has removed Kelihos from 28,000 of the estimated 41,000 machines running the original bot.

Boscovich estimated the current size of the botnet's infected fleet to be less than 10,000, but could not give any estimate for the size of the new one.

The botnet was used to send spam, harvest user information and promote illegal websites, such as sites containing child exploitation material as well as counterfeit pharmaceuticals.

Follow @CSO_Australia

Join the CSO newsletter!

Error: Please check your email address.

More about etworkKasperskyKasperskyMicrosoft

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by Liam Tung

Latest Videos

  • 150x50

    CSO Webinar: The Human Factor - Your people are your biggest security weakness

    ​Speakers: David Lacey, Researcher and former CISO Royal Mail David Turner - Global Risk Management Expert Mark Guntrip - Group Manager, Email Protection, Proofpoint

    Play Video

  • 150x50

    CSO Webinar: Current ransomware defences are failing – but machine learning can drive a more proactive solution

    Speakers • Ty Miller, Director, Threat Intelligence • Mark Gregory, Leader, Network Engineering Research Group, RMIT • Jeff Lanza, Retired FBI Agent (USA) • Andy Solterbeck, VP Asia Pacific, Cylance • David Braue, CSO MC/Moderator What to expect: ​Hear from industry experts on the local and global ransomware threat landscape. Explore a new approach to dealing with ransomware using machine-learning techniques and by thinking about the problem in a fundamentally different way. Apply techniques for gathering insight into ransomware behaviour and find out what elements must go into a truly effective ransomware defence. Get a first-hand look at how ransomware actually works in practice, and how machine-learning techniques can pick up on its activities long before your employees do.

    Play Video

  • 150x50

    CSO Webinar: Get real about metadata to avoid a false sense of security

    Speakers: • Anthony Caruana – CSO MC and moderator • Ian Farquhar, Worldwide Virtual Security Team Lead, Gigamon • John Lindsay, Former CTO, iiNet • Skeeve Stevens, Futurist, Future Sumo • David Vaile - Vice chair of APF, Co-Convenor of the Cyberspace Law And Policy Community, UNSW Law Faculty This webinar covers: - A 101 on metadata - what it is and how to use it - Insight into a typical attack, what happens and what we would find when looking into the metadata - How to collect metadata, use this to detect attacks and get greater insight into how you can use this to protect your organisation - Learn how much raw data and metadata to retain and how long for - Get a reality check on how you're using your metadata and if this is enough to secure your organisation

    Play Video

  • 150x50

    CSO Webinar: How banking trojans work and how you can stop them

    CSO Webinar: How banking trojans work and how you can stop them Featuring: • John Baird, Director of Global Technology Production, Deutsche Bank • Samantha Macleod, GM Cyber Security, ME Bank • Sherrod DeGrippo, Director of Emerging Threats, Proofpoint (USA)

    Play Video

  • 150x50

    IDG Live Webinar:The right collaboration strategy will help your business take flight

    Speakers - Mike Harris, Engineering Services Manager, Jetstar - Christopher Johnson, IT Director APAC, 20th Century Fox - Brent Maxwell, Director of Information Systems, THE ICONIC - IDG MC/Moderator Anthony Caruana

    Play Video

More videos

Blog Posts