New version of Gozi financial malware bundles MBR rootkit

The malware installs code into the computer's master boot record in order to achieve persistence, Trusteer researchers say

Researchers from security firm Trusteer have found a new variant of the Gozi banking Trojan program that infects a computer's Master Boot Record (MBR) in order to achieve persistence.

The Master Boot Record (MBR) is a boot sector that resides at the beginning of a storage drive and contains information about how that drive is partitioned. It also includes boot code that runs before the operating system starts.

Some malware authors have leveraged the MBR in order to give their malicious programs a head start over antivirus programs installed on the computer.

Sophisticated malware that uses MBR rootkit components, like TDL4, also known as Alureon or TDSS, are part of the reason why Microsoft built the Secure Boot feature into Windows 8. This malware is hard to detect and remove and can even survive operating system reinstallation procedures.

"Even though MBR rootkits are considered highly effective they haven't been integrated into a lot of financial malware," Trusteer researcher Etay Maor said Thursday in a blog post. "One exception was Mebroot rootkit that was used to deploy Torpig (aka Sinowal/Anserin)."

The new Gozi MBR rootkit component waits for Internet Explorer to be launched and then injects malicious code into the process. This allows the malware to intercept traffic and perform Web injections inside the browser like most financial Trojans programs do, Maor said.

The fact that a new variant of Gozi was discovered shows that cybercriminals continue to use this threat despite the fact that its main developer and some of his accomplices were arrested and indicted.

The new variant detected by the Trusteer researchers is very similar to an older version, except for the additional MBR rootkit component, Maor said. "This may indicate that a new rootkit is being sold in the cybercriminals' forums and is adopted by malware authors."

While some dedicated tools for removing MBR rootkits do exist, many experts recommend wiping the entire hard drive and recreating the partitions in order to ensure a clean start if the computer has been infected with such a threat, Maor said.

Since cleaning such malware might require advanced technical knowledge, it's probably best to contact the technical support department of your antivirus provider in order to get expert help.

Join the PC World newsletter!

Error: Please check your email address.
Rocket to Success - Your 10 Tips for Smarter ERP System Selection

Tags Trusteersecurityspywaremalware

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 Articles

Resources

PCW Evaluation Team

Matthew Stivala

HP OfficeJet 250 Mobile Printer

The HP OfficeJet 250 Mobile Printer is a great device that fits perfectly into my fast paced and mobile lifestyle. My first impression of the printer itself was how incredibly compact and sleek the device was.

Armand Abogado

HP OfficeJet 250 Mobile Printer

Wireless printing from my iPhone was also a handy feature, the whole experience was quick and seamless with no setup requirements - accessed through the default iOS printing menu options.

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.

Featured Content

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?