Updates to this story
For a while insecurity experts have said that Stuxnet was designed by foreign powers to sabotage centrifuges used in Iran's nuclear-enrichment programme.
Now Iranian President Mahmoud Ahmadinejad has admitted that the worm had managed to do that and put Iran's nuclear-enrichment programme on hold.
He said yesterday that the malicious computer code launched by "enemies" of the state had installed the worm at the Natanz nuclear facility.Natanz is engaged in enriching uranium that could be used to manufacture weapons.
Although Ahmadinejad did not mention Natanz he did say that malware had "succeeded in creating problems for a limited number of our centrifuges."
The United Nations' International Atomic Energy Agency, said that Iran had temporarily halted uranium enrichment at its Natanz plant for unknown reasons earlier this month. Thousands of centrifuges reportedly stopped production as a result.
Ahmadinejad said the malware that caused problems with its centrifuges was in software that the attackers had "installed in electronic parts." He claimed the infection had been halted.
He insisted that the the glorious security experts of the Iranian revolution had stopped Stuxnet and made sure that such an attack would not happen again.
Of course Ahmadinejad blamed Israel for the attack. While it is a good bet, Ahmadinejad tends to blame Israel for everything ranging from global warming, to it being a bit cold this winter.
The Stuxnet worm infected more than 100,000 computer systems worldwide, most of them in Iran. It attacked Siemens Simatic WinCC SCADA systems. The Siemens system is used in various facilities to manage pipelines, nuclear plants and various utility and manufacturing equipment.