Wednesday, April 16, 2008
Malicious microprocessor LEON opens new doors for attack
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."
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.
