The Stuxnet worm wasn't the only super secret worm around. Turns out, it had an evil secret twin. According to a report published in Foreign Policy, the original Stuxnet variant was a more sophisticated and potentially more powerful worm than Stuxnet itself.

The older twin targeted centrifuges at the Natanz uranium enrichment plant but did so by blocking the outflow of gas from the cascades of centrifuges, causing pressure to build up and the equipment to become damages. It masked the attack by looping 21 seconds of the system's sensor values so that engineers at the facility wouldn't realize that there was anything wrong.

As FP's Ralph Langner suggests, though, "The dramatic differences between both versions point to changing priorities that most likely were accompanied by a change in stakeholders." In other words, the attackers' posse got bigger.

The discovery of Stuxnet's evil twin makes one thing frighteningly true: there are weapons like these already out there, lurking in the darkness. And we don't know what kind of damage it will do when it is set to go off. [FP]

Image via AP