Warning after Zeus bank Trojan fused with Ramnit worm

Hybrid is a spreading menace

Researchers have uncovered evidence that the infamous Zeus login-stealing Trojan has been blended with the Ramnit worm to create hybrid malware that can attack online bank accounts while spreading across networks.

Security company Trusteer said it recently discovered a mutant version of Ramnit that appeared to be using a man-in-the-browser (MitB) web injection module to trick bank customers into handing over their logins details, a technique straight out of the Zeus (aka 'SpyEye') design book.

The company has not yet established that the malware’s source code was definitely from Zeus, but is confident that there was now enough circumstantial evidence to suggest that it was.

The Zeus source code is believed to have become widely available in criminal circles in May after a leak of unconfirmed origin so security watchers have been on the lookout for new malware incorporating some of its most powerful and often very specific features. Trusteer is convinced that the Ramnit variant is the first recorded example of that.

Ramnit itself is an unremarkable worm so why criminals might want to combine it with Zeus is open to speculation.

“Zeus does not have its own propagation mechanism,” said Trusteer’s CTO, Amit Klein. “The author might be going after networks,” he explained, noting that the hybrid malware had the ability to spread the Zeus data stealing across network shares, a potentially powerful new ability.

If the malware turns out to have incorporated Zeus, it suggested that more malware using it would appear in the coming months, he added.

“We are seeing it [Ramnit] across multiple regions, especially in the UK and the US. It is going well,” said Klein, confirming that an unknown but significant number of infected PCs in these countries had been infected, presumably a conclusion culled from an analysis of logs on its German-hosted command and control servers.

The behaviour of the new Ramnit is certainly consistent with Zeus, which typically attacks a range of banks, particularly those in countries where Internet banking is well established such as the UK and the US.

“Unlike the past, when financial institutions had to defend against a limited number of malware platforms, attacks can now come from virtually any malicious software program - old or new. The malware distribution channel for fraudsters has increased in scale significantly.”     

A fuller analysis of the new malware and its connections with Zeus can be found on Trusteer’s website. The new version is detected - and not detected - by the same spread of of antivirus products that detected older versions of Zeus, which is to say only by some.

Join the CSO newsletter!

Error: Please check your email address.

Tags Trusteerinternet bankingzeusRamnittrojanmalwarecybercrimefraud

Show Comments

Featured Whitepapers

Editor's Recommendations

Solution Centres

Stories by John E. Dunn

Latest Videos

  • 150x50

    CSO Webinar: Will your data protection strategy be enough when disaster strikes?

    Speakers: - Paul O’Connor, Engagement leader - Performance Audit Group, Victorian Auditor-General’s Office (VAGO) - Nigel Phair, Managing Director, Centre for Internet Safety - Joshua Stenhouse, Technical Evangelist, Zerto - Anthony Caruana, CSO MC & Moderator

    Play Video

  • 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

More videos

Blog Posts

Market Place