BLACK HAT - Hackers find a new place to hide rootkits

Proof-of-concept System Management Mode rootkit developed for upcoming show.

Security researchers have developed a new type of malicious rootkit software that hides itself in an obscure part of a computer's microprocessor, hidden from current antivirus products.

Called a System Management Mode (SMM) rootkit, the software runs in a protected part of a computer's memory that can be locked and rendered invisible to the operating system, but which can give attackers a picture of what's happening in a computer's memory.

The SMM rootkit comes with keylogging and communications software and could be used to steal sensitive information from a victim's computer. It was built by Shawn Embleton and Sherri Sparks, who run an Oviedo, Florida, security company called Clear Hat Consulting.

The proof-of-concept software will be demonstrated publicly for the first time at the Black Hat security conference in Las Vegas this August.

The rootkits used by cyber crooks today are sneaky programs designed to cover up their tracks while they run in order to avoid detection. Rootkits hit the mainstream in late 2005 when Sony BMG Music used rootkit techniques to hide its copy protection software. The music company was ultimately forced to recall millions of CDs amid the ensuing scandal.

In recent years, however, researchers have been looking at ways to run rootkits outside of the operating system, where they are much harder to detect. For example, two years ago researcher Joanna Rutkowska introduced a rootkit called Blue Pill, which used AMD's chip-level virtualization technology to hide itself. She said the technology could eventually be used to create "100 percent undetectable malware."

"Rootkits are going more and more toward the hardware," said Sparks, who wrote another rootkit three years ago called Shadow Walker. "The deeper into the system you go, the more power you have and the harder it is to detect you."

Blue Pill took advantage of new virtualization technologies that are now being added to microprocessors, but the SMM rootkit uses a feature that has been around for much longer and can be found in many more machines. SMM dates back to Intel's 386 processors, where it was added as a way to help hardware vendors fix bugs in their products using software. The technology is also used to help manage the computer's power management, taking it into sleep mode, for example.

In many ways, an SMM rootkit, running in a locked part of memory, would be more difficult to detect than Blue Pill, said John Heasman, director of research with NGS Software, a security consulting firm. "An SMM rootkit has major ramifications for things like [antivirus software products]," he said. "They will be blind to it."

Researchers have suspected for several years that malicious software could be written to run in SMM. In 2006, researcher Loic Duflot demonstrated how SMM malware would work. "Duflot wrote a small SMM handler that compromised the security model of the OS," Embleton said. "We took the idea further by writing a more complex SMM handler that incorporated rootkit-like techniques."

In addition to a debugger, Sparks and Embleton had to write driver code in hard-to-use assembly language to make their rootkit work. "Debugging it was the hardest thing," Sparks said.

Being divorced from the operating system makes the SMM rootkit stealthy, but it also means that hackers have to write this driver code expressly for the system they are attacking.

"I don't see it as a widespread threat, because it's very hardware-dependent," Sparks said. "You would see this in a targeted attack."

But will it be 100 percent undetectable? Sparks says no. "I'm not saying it's undetectable, but I do think it would be difficult to detect." She and Embleton will talk more about detection techniques during their Black Hat session, she said.

Brand new rootkits don't come along every day, Heasman said. "It will be one of the most interesting, if not the most interesting, at Black Hat this year," he said.

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

Robert McMillan

IDG News Service
Comments are now closed.

Latest News Articles

Most Popular Articles

Follow Us

GGG Evaluation Team

Kathy Cassidy

STYLISTIC Q702

First impression on unpacking the Q702 test unit was the solid feel and clean, minimalist styling.

Anthony Grifoni

STYLISTIC Q572

For work use, Microsoft Word and Excel programs pre-installed on the device are adequate for preparing short documents.

Steph Mundell

LIFEBOOK UH574

The Fujitsu LifeBook UH574 allowed for great mobility without being obnoxiously heavy or clunky. Its twelve hours of battery life did not disappoint.

Andrew Mitsi

STYLISTIC Q702

The screen was particularly good. It is bright and visible from most angles, however heat is an issue, particularly around the Windows button on the front, and on the back where the battery housing is located.

Simon Harriott

STYLISTIC Q702

My first impression after unboxing the Q702 is that it is a nice looking unit. Styling is somewhat minimalist but very effective. The tablet part, once detached, has a nice weight, and no buttons or switches are located in awkward or intrusive positions.

Resources

Best Deals on GoodGearGuide

Compare & Save

Deals powered by WhistleOut
Use WhistleOut's technology to compare:
Mobile phone plans & deals
Mobile phone models
Mobile phone carriers
Broadband plans & deals
Broadband providers
Deals powered by WhistleOut
WhistleOut

Latest Jobs

Don’t have an account? Sign up here

Don't have an account? Sign up now

Forgot password?