New rootkit uses old trick to hide itself

Over the past month a new type of malicious software has emerged, called a master boot record rootkit.

Over the past month, a new type of malicious software has emerged, using a decades-old technique to hide itself from antivirus software.

The malware, called Trojan.Mebroot by Symantec, installs itself on the first part of the computer's hard drive to be read on startup, then makes changes to the Windows kernel, making it hard for security software to detect it.

Criminals have been installing Trojan.Mebroot, known as a master boot record rootkit, since mid-December, and were able to infect nearly 5,000 users in two separate attacks, staged on Dec. 12 and Dec. 19, according to Verisign's iDefense Intelligence Team. In order to install the software on a victim's computer, attackers first lure them to a compromised Web site, which then launches a variety of attacks against the victim's computer in hopes of finding a way to run the rootkit code on the PC.

Once installed, the malware gives attackers control over the victim's machine.

The group behind this latest rootkit is the same one responsible for the Torpig Trojan, and it is believed to have already installed more than 250,000 Trojan programs, iDefense said in a report on the rootkit published Monday.

The interesting thing about Trojan.Mebroot is that it installs itself on the master boot record (MBR). This is the first sector of the computer's hard drive and it is the place the computer goes to first whenever it wants to boot up the operating system. "Basically, if you can control the MBR, you can control the operating system and therefore the computer it resides on," wrote Symantec researcher Elia Florio in a blog posting on Trojan.Mebroot.

The criminals are using several different versions of this attack code, some of which are not currently being detected by some antivirus products, iDefense said.

"At the moment the AV detection is hit and miss across the board, however in the last day a number of vendors have added detection for it already," said Andrew Storms, director of security operations with nCircle Network Security. "As for penetration, so far many people are showing it as having a low overall distribution. The concern is that the group which may be preparing to distribute the rootkit is well-prepared."

Malicious software that infected the master boot record was common during the MS-DOS era, but it has not been used much in attacks in recent years.

In 2005, however, researchers at eEye Digital Security gave a talk at the Black Hat security conference, showing how a rootkit could hide itself on the MBR. This Trojan.Mebroot software is derived from that code, iDefense said.

Getting this kind of malicious software to work reliably is a technical challenge, and there have generally been easier ways for the bad guys to take over PCs in recent years, said Marc Maiffret, an independent security researcher who was chief technology officer at eEye when the code was first developed.

Attackers were given a hand last year, however, when researchers at NV Labs published a proof of concept MBR rootkit.

Maiffret said that while we may soon see more of these MBR rootkits, "it won't take long for all the antivirus companies to react."

"It's not some new attack vector that's going to be hard to prevent," he said. "It's just something that people haven't really paid attention to."

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

Robert McMillan

IDG News Service
Show Comments

Cool Tech

Toys for Boys

Family Friendly

Stocking Stuffer

SmartLens - Clip on Phone Camera Lens Set of 3

Learn more >

Christmas Gift Guide

Click for more ›

Brand Post

Most Popular Reviews

Latest Articles

Resources

PCW Evaluation Team

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!

Cathy Giles

Brother MFC-L8900CDW

The Brother MFC-L8900CDW is an absolute stand out. I struggle to fault it.

Luke Hill

MSI GT75 TITAN

I need power and lots of it. As a Front End Web developer anything less just won’t cut it which is why the MSI GT75 is an outstanding laptop for me. It’s a sleek and futuristic looking, high quality, beast that has a touch of sci-fi flare about it.

Emily Tyson

MSI GE63 Raider

If you’re looking to invest in your next work horse laptop for work or home use, you can’t go wrong with the MSI GE63.

Featured Content

Product Launch Showcase

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?