Shylock banking malware updated to spread via Skype, researchers say

A new component allows the Shylock Trojan program to send messages and files through Skype

The Shylock home banking malware has been updated with new functionality that allows it to spread automatically using the popular Skype Voice-over-IP (VoIP) and instant messaging client.

Shylock, named after a character from Shakespeare's "The Merchant of Venice," is a Trojan program discovered in 2011 that steals online banking credentials and other financial information from infected computers.

According to security researchers from CSIS Security Group, a Denmark-based IT security firm, the malware's new Skype-related functionality was added earlier this week in the form of a plug-in called "msg.gsm."

The new plug-in allows the malware to send rogue messages and files through Skype and delete them from the application's history, CSIS partner and security specialist Peter Kruse said Thursday in a blog post.

The plug-in also bypasses the warning and confirmation request that Skype displays when a third-party program tries to connect and interact with the application.

"Shylock is one of the most advanced Trojan-banker [malware] currently being used in attacks against home banking systems," Kruse said. "The code is constantly being updated and new features are added regularly."

The Shylock authors appear to target users from specific regions of the world. According to a map showing the distribution of Shylock infections that was published by CSIS, there's a high concentration of victims in the U.K. However, there are also many Shylock-infected computers throughout mainland Europe and the U.S.

The use of Skype for distribution allows Shylock's authors to maintain their geographic focus, Kruse said. Previous cases of malware spreading through MSN Messenger, Yahoo Messenger, or other real-time chat programs, have resulted in local infection outbreaks because people have a tendency to stay connected with friends located in the same region, he said.

Last week, Microsoft announced that it plans to retire its Messenger service globally on March 15 and advised users to switch to Skype, a product the company has owned since 2011. The fact that Shylock's authors decided to start using Skype as a distribution platform soon after this announcement might not be just a coincidence, Kruse said.

Aside from spreading through Skype, Shylock can also copy itself to removable drives and local network shares, Kruse said.

Join the PC World newsletter!

Error: Please check your email address.

Tags online safetyMicrosoftsecurityDesktop securityCSIS Security Groupmalwarefraud

Our Back to Business guide highlights the best products for you to boost your productivity at home, on the road, at the office, or in the classroom.

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

Lucian Constantin

IDG News Service
Show Comments

Most Popular Reviews

Latest News Articles

Resources

PCW Evaluation Team

Azadeh Williams

HP OfficeJet Pro 8730

A smarter way to print for busy small business owners, combining speedy printing with scanning and copying, making it easier to produce high quality documents and images at a touch of a button.

Andrew Grant

HP OfficeJet Pro 8730

I've had a multifunction printer in the office going on 10 years now. It was a neat bit of kit back in the day -- print, copy, scan, fax -- when printing over WiFi felt a bit like magic. It’s seen better days though and an upgrade’s well overdue. This HP OfficeJet Pro 8730 looks like it ticks all the same boxes: print, copy, scan, and fax. (Really? Does anyone fax anything any more? I guess it's good to know the facility’s there, just in case.) Printing over WiFi is more-or- less standard these days.

Ed Dawson

HP OfficeJet Pro 8730

As a freelance writer who is always on the go, I like my technology to be both efficient and effective so I can do my job well. The HP OfficeJet Pro 8730 Inkjet Printer ticks all the boxes in terms of form factor, performance and user interface.

Michael Hargreaves

Windows 10 for Business / Dell XPS 13

I’d happily recommend this touchscreen laptop and Windows 10 as a great way to get serious work done at a desk or on the road.

Aysha Strobbe

Windows 10 / HP Spectre x360

Ultimately, I think the Windows 10 environment is excellent for me as it caters for so many different uses. The inclusion of the Xbox app is also great for when you need some downtime too!

Mark Escubio

Windows 10 / Lenovo Yoga 910

For me, the Xbox Play Anywhere is a great new feature as it allows you to play your current Xbox games with higher resolutions and better graphics without forking out extra cash for another copy. Although available titles are still scarce, but I’m sure it will grow in time.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?