Malicious Microprocessor Opens New Doors for Attack

KAMIS, 17 APRIL 2008

For years, hackers have focused on finding bugs in computer software that give them unauthorized access to computer systems, but now there's another way to break in: Hack the microprocessor.

On Tuesday, researchers at the University of Illinois at Urbana-Champaign demonstrated how they altered a computer chip to grant attackers back-door access to a computer. It would take a lot of work to make this attack succeed in the real world, but it would be virtually undetectable.

To launch its attack, the team used a special programmable processor running the Linux operating system. The chip was programmed to inject malicious firmware into the chip's memory, which then allows an attacker to log into the machine as if he were a legitimate user. To reprogram the chip, researchers needed to alter only a tiny fraction of the processor circuits. They changed 1,341 logic gates on a chip that has more than 1 million of these gates in total, said Samuel King, an assistant professor in the university's computer science department.

"This is like the ultimate back door," said King. "There were no software bugs exploited."

King demonstrated the attack on Tuesday at the Usenix Workshop on Large-Scale Exploits and Emergent Threats, a conference for security researchers held in San Francisco.

His team was able to add the back door by reprogramming a small number of the circuits on a LEON processor running the Linux operating system. These programmable chips are based on the same Sparc design that is used in Sun Microsystems' midrange and high-end servers. They are not widely used, but have been deployed in systems used by the International Space Station.

In order to hack into the system, King first sent it a specially crafted network packet that instructed the processor to launch the malicious firmware. Then, using a special login password, King was able to gain access to the Linux system. "From the software's perspective, the packet gets dropped... and yet I have full and complete access to this underlying system that I just compromised," King said.

The researchers are now working on tools that could help detect such a malicious processor, but there's a big problem facing criminals who would try to reproduce this type of attack in the real world. How do you get a malicious CPU onto someone's machine?

This would not be easy, King said, but there are a few possible scenarios. For example, a "mole" developer could add the code while working on the chip's design, or someone at a computer assembly plant could be paid off to install malicious chips instead of legitimate processors. Finally, an attacker could create a counterfeit version of a PC or a router that contained the malicious chip.

"This is not a script kiddie attack," he said. "It's going to require an entity with resources."

Though such a scenario may seem far-fetched, the U.S. Department of Defense (DoD) is taking the issue seriously. In a February 2005 report, the DoD's Defense Science Board warned of the very attack that the University of Illinois researchers have developed, saying that a shift toward offshore integrated circuit manufacturing could present a security problem.

There are already several examples of products that have shipped with malicious software installed. In late 2006, for example, Apple shipped Video iPods that contained the RavMonE.exe virus.

"We're seeing examples of the overall supply chain being compromised," King said. "Whether or not people will modify the overall processor designs remains to be seen."

A security problem with MySpace

KAMIS, 17 APRIL 2008

A security problem with MySpace has the potential to botch up law-enforcement efforts to track bad actors on the social-networking site.

An increasing number of MySpace profiles contain a few lines of code that automatically subscribe people to the profile's video channel, said Chris Boyd, security research manager for FaceTime Communications.

After the visitor has been added, the person running the profile can see the subscribers. For people who don't abuse MySpace, the problem may not appear to be a huge deal, Boyd said.

But hackers often are running dozens of "puppet" MySpace accounts, which are used for a variety of malicious acts such as spamming or trying to vandalize other profiles, not for social networking, Boyd said.

So when a visitor is added, it's a tip-off that someone could be tracking their movements in order to expose them for abusing MySpace, Boyd said.

Hackers "are using every trick in the book they can to know who is watching them," said Boyd, who has posted more details on his blog.

That's particularly bad for law enforcement, which may invest weeks in "digital stakeouts" observing certain profiles as part of pedophilia investigations, Boyd said.

Hackers have been inserting the code on their pages since at least October 2007. MySpace was notified of the problem in late March but has yet to fix it, although Boyd said the company sent him a personal e-mail labeling the problem a "system error."

The code doesn't tell the person running the profile how many times a particular visitor comes to their site or when, Boyd said. But in combination with an IP (Internet protocol) address "tracker," a profile owner could compile a more complete picture of visitors.

MySpace prohibits tools such as IP trackers, which can narrow down to certain geographic areas where visitors are based. Many of the trackers advertised on dodgy forums simply don't work, Boyd said. Nonetheless, hackers keep finding ways to game MySpace.

There are a couple defenses against this latest problem. If you're automatically added to someone's video channel, you can simply unsubscribe and avoid going back to the profile until MySpace has fixed it.

Another defense is adding the URL (Uniform Resource Locator) "vids.myspace.com" to the "hosts" file, an internal PC file that matches domain names with Web sites. The file can be configured to block any domains a user specifies.