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 newsletter!

Or

Sign up to gain exclusive access to email subscriptions, event invitations, competitions, giveaways, and much more.

Membership is free, and your security and privacy remain protected. View our privacy policy before signing up.

Error: Please check your email address.

Tags Personal TechTrusteer

Keep up with the latest tech news, reviews and previews by subscribing to the Good Gear Guide newsletter.

John E Dunn

Techworld
Show Comments

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

Jack Jeffries

MSI GS75

As the Maserati or BMW of laptops, it would fit perfectly in the hands of a professional needing firepower under the hood, sophistication and class on the surface, and gaming prowess (sports mode if you will) in between.

Taylor Carr

MSI PS63

The MSI PS63 is an amazing laptop and I would definitely consider buying one in the future.

Christopher Low

Brother RJ-4230B

This small mobile printer is exactly what I need for invoicing and other jobs such as sending fellow tradesman details or step-by-step instructions that I can easily print off from my phone or the Web.

Aysha Strobbe

Microsoft Office 365/HP Spectre x360

Microsoft Office continues to make a student’s life that little bit easier by offering reliable, easy to use, time-saving functionality, while continuing to develop new features that further enhance what is already a formidable collection of applications

Michael Hargreaves

Microsoft Office 365/Dell XPS 15 2-in-1

I’d recommend a Dell XPS 15 2-in-1 and the new Windows 10 to anyone who needs to get serious work done (before you kick back on your couch with your favourite Netflix show.)

Maryellen Rose George

Brother PT-P750W

It’s useful for office tasks as well as pragmatic labelling of equipment and storage – just don’t get too excited and label everything in sight!

Featured Content

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?