Iranian president Mahmoud Ahmadinejad admitted Monday that a virus has damaged computers throughout Iran and created problems in centrifuges that are involved in enrichment of uranium in several nuclear sites.

 Iran's enemies “succeeded in creating problems for a limited number of our centrifuges with the software they had installed in electronic parts,” Ahmadinejad told reporters. “They did a bad thing. Fortunately our experts discovered that and today they are not able (to do that) anymore," he said.
This is the first time that Iran has officially admitted that its enemies are responsible for damaging its nuclear program by means of a computer virus. 
Less than one week ago it was reported that major technical problems in Iran's nuclear program forced the shutdown of thousands of centrifuges enriching uranium at Iran's Natanz plant. Diplomats said the problems caused Iranian experts to “briefly power down” the machines they use for enrichment.
The sources said they did not have further details but suspicions focused on the Stuxnet worm, the computer virus which has recently plagued Iran's nuclear program, and is believed by many observers to have been unleashed by the US or Israel. 
Experts said that the Stuxnet worm was designed to destroy centrifuges by sending them spinning out of control and then slowing them down abruptly to a near halt. There has been speculation that either the United States or Israel is responsible for the virus, which is said to be so sophisticated that no amateur or group of amateurs would have been able to devise it.