How an intelligent computer worm struck Iran's super-weapon

In the 20th century, this would have been a job for James Bond.

The mission: Infiltrate the highly advanced, securely guarded enemy headquarters where scientists in the clutches of an evil master are secretly building a weapon that can destroy the world. Then render that weapon harmless and escape undetected.

But in the 21st century, Bond doesn't get the call. Instead, the job is handled by a suave and very sophisticated secret computer worm, a jumble of code called Stuxnet, which in the last year has not only crippled Iran's nuclear program but has caused a major rethinking of computer security around the globe.

Intelligence agencies, computer security companies and the nuclear industry have been trying to analyze the worm since it was discovered in June by a Belarus-based company that was doing business in Iran. And what they've all found, says Sean McGurk, the Homeland Security Department's acting director of national cyber security and communications integration, is a “game changer.”

The construction of the worm was so advanced, it was “like the arrival of an F-35 into a World War I battlefield,” says Ralph Langner, the computer expert who was the first to sound the alarm about Stuxnet. Others have called it the first “weaponized” computer virus.

Simply put, Stuxnet is an incredibly advanced, undetectable computer worm that took years to construct and was designed to jump from computer to computer until it found the specific, protected control system that it aimed to destroy: Iran’s nuclear enrichment program.

The target was seemingly impenetrable; for security reasons, it lay several stories underground and was not connected to the World Wide Web. And that meant Stuxnet had to act as sort of a computer cruise missile: As it made its passage through a set of unconnected computers, it had to grow and adapt to security measures and other changes until it reached one that could bring it into the nuclear facility.

When it ultimately found its target, it would have to secretly manipulate it until it was so compromised it ceased normal functions.

And finally, after the job was done, the worm would have to destroy itself without leaving a trace.

That is what we are learning happened at Iran's nuclear facilities -- both at Natanz, which houses the centrifuge arrays used for processing uranium into nuclear fuel, and, to a lesser extent, at Bushehr, Iran's nuclear power plant.