Former UN nuclear boss hints at Stuxnet’s Iran hit

The Stuxnet virus may have significantly damaged Iran’s nuclear capability, according to a top former United Nations nuclear inspector.

The Stuxnet virus targets industrial systems and was already rumoured to have targeted Iran’s much-mistrusted uranium enrichment programme.

Olli Heinonen, who quit as the head of the UN nuclear inspections team in August, said there had been a spate of equipment failures in Iran in the wake of the virus, which was first discovered in June this year.

According to figures from the International Atomic Energy Agency, Iran’s arsenal of working high-speed centrifuges that are required to produce enriched uranium had fallen from 3,936 to 3,772 in just a few months.

Stuxnet changes the output frequencies and thus the speed of the motors for short intervals over periods of months. Interfering with the speed of the motors sabotages the normal operation of the industrial control process

“Stuxnet could be one of the reasons,” Heinonen told Reuters, although he admitted the were no facts to rule out coincidence. “There is no evidence that it was, but there has been quite a lot of malfunctioning centrifuges.”

Stuxnet has been described as one of the most complex viruses ever created, leading to widespread speculation that it involved nation state sponsorship.

Heinonen’s comments follow research published last week by Symantec in which the security company claimed it could prove that the infamous Stuxnet was targeting specific mechanical device controls via computer.

According to the company, the payload targets frequency converter drives that are used to control the speed of motors in devices such as centrifuges.

“A frequency converter drive is a power supply that can change the frequency of the output, which controls the speed of a motor,” Symantec said in its blog.

“Stuxnet changes the output frequencies and thus the speed of the motors for short intervals over periods of months. Interfering with the speed of the motors sabotages the normal operation of the industrial control process.”

The company said that to have an impact Stuxnet required the industrial control system to have frequency converter drives from at least one of two specific vendors, one headquartered in Finland and the other in Tehran.