Feeds

Excuse me sir: there's a rootkit in your master boot record

Undetected by most AV apps

Reducing security risks from open source software

Security mavens have uncovered a new class of attacks that attach malware to the bowels of a hard drive, making it extremely hard to detect and even harder to remove.

The rootkit modifies a PC's master boot record (MBR), which is the first sector of a storage device and is used to help a PC locate an operating system to boot after it is turned on. The result: the rootkit is running even before Windows loads. There have been more than 5,000 infections in less than a month, researchers say.

"Master boot record rootkits are able to subvert the Windows kernel before it loads, which gives it a distinct stealth advantage over rootkits that load while Windows is running," said Matthew Richard, director of the rapid response team for iDefense, a security provider owned by VeriSign. "It gives it a great stealth mechanism that allows it to persist even after removal." Such rootkits can even survive reinstallation of the operating system, he said.

Because the rootkit lurks deep within the hard drive, well below the operating system, most antivirus programs don't detect the malware. Symantec's antivirus program is an exception, however. It labels the pest Trojan.Mebroot, according to Javier Santoyo, a senior manager for emerging technologies at Symantec.

The new rootkit is part of the arms race between security vendors and malware writers, he said. "We're definitely making it harder and harder for the bad guys to do stuff to the operating system," he said. They respond by attacking new parts of a PC.

Every version of Windows, including Vista, is vulnerable to the rootkit.

About 30,000 websites, mostly located in Europe, are actively trying to install the rootkit by exploiting users who have failed to install Windows updates, Richard says. There were 5,000 infections from December 12 to January 7. The rootkit is being spread by the same group responsible for distributing the Torpig banking Trojans, which are used to steal online banking credentials.

While the number of infections is relatively low, the number could rise quickly if the group expanded the number of exploits it used.

MBR-based attacks date back to the days of MS-DOS, when viruses such as Brain, Stoned, Tequila caused mischief by hiding themselves in a hard drive's primary partition. In 2005, researchers from eEye Digital Security demonstrated a proof of concept that showed how the technique could be extended to the Windows NT domain.

The rootkit comes as a wake-up call, demonstrating that new measures are needed to protect PC security. Many motherboard makers still don't provide functionality that prevents the overwriting of an MBR. But even when such capabilities do exist, the average user has no idea how to enable them. And even when they're enabled, malware writers are likely to target even deeper recesses within a PC.

"We will never win the battle with malware, especially rootkits, without a help from hardware and changes in the *design* of the OSes," Joanna Rutkowska, a researcher specializing in rootkits, wrote in an email. ®

Mobile application security vulnerability report

More from The Register

next story
LibreSSL RNG bug fix: What's all the forking fuss about, ask devs
Blow to bit-spitter 'tis but a flesh wound, claim team
Microsoft: You NEED bad passwords and should re-use them a lot
Dirty QWERTY a perfect P@ssword1 for garbage websites
Manic malware Mayhem spreads through Linux, FreeBSD web servers
And how Google could cripple infection rate in a second
NUDE SNAPS AGENCY: NSA bods love 'showing off your saucy selfies'
Swapping other people's sexts is a fringe benefit, says Snowden
Own a Cisco modem or wireless gateway? It might be owned by someone else, too
Remote code exec in HTTP server hands kit to bad guys
British data cops: We need greater powers and more money
You want data butt kicking, we need bigger boots - ICO
Crooks fling banking Trojan at Japanese smut site fans
Wait - they're doing online banking with an unpatched Windows PC?
NIST told to grow a pair and kick NSA to the curb
Lrn2crypto, oversight panel tells US govt's algorithm bods
prev story

Whitepapers

Top three mobile application threats
Prevent sensitive data leakage over insecure channels or stolen mobile devices.
The Essential Guide to IT Transformation
ServiceNow discusses three IT transformations that can help CIO's automate IT services to transform IT and the enterprise.
Mobile application security vulnerability report
The alarming realities regarding the sheer number of applications vulnerable to attack, and the most common and easily addressable vulnerability errors.
How modern custom applications can spur business growth
Learn how to create, deploy and manage custom applications without consuming or expanding the need for scarce, expensive IT resources.
Consolidation: the foundation for IT and business transformation
In this whitepaper learn how effective consolidation of IT and business resources can enable multiple, meaningful business benefits.