By Glenn Kessler
Washington Post Staff Writer
Monday, November 15, 2010; 6:30 PM
The Stuxnet computer worm that infiltrated industrial systems in Iran this fall may have been designed specifically to attack the country's nuclear program, potentially crippling centrifuges used to enrich uranium gas, according to new research.
In a blog post late last week, a Stuxnet researcher at Symantec wrote that the software firm had concluded that the worm targeted industrial systems with high frequency "converter drives" from two specific vendors, including one in Iran.
Independently, Langner Communications of Germany, a systems security firm, also announced over the weekend that another part of the worm's attack code was configured in a way to target a control system for steam turbines used in power plants, such as those installed at the Bushehr nuclear power plant in Iran. Langner also confirmed that the worm appeared to attack key components of centrifuges.
Ivanka Barzashka, a research associate at the Federation of American Scientists, said the Symantec findings "if true, are very significant."
In an e-mail, Barzashka wrote that the targeted frequency range, from 807 megahertz to 1210 megahertz, "is consistent with the operational frequencies of gas centrifuges used for uranium enrichment."
"Centrifuges are delicate pieces of equipment," she said. "There is a huge incentive for pushing the machines to operate at the maximum speed allowed by the materials they are made of. In addition, before they reach their maximum operating speeds, centrifuges have to traverse certain 'critical frequencies' at which they encounter resonance and can fly apart."
"Rigging the speed control is a very clever way of causing the machines to fly apart," she added. "If Symantec's analysis is true, then Stuxnet likely aimed to destroy Iran's gas centrifuges, which could produce enriched uranium for both nuclear fuel and nuclear bombs."
After the discovery of the Stuxnet virus, analysts said it was likely the creation of a sophisticated entity, namely a government agency. Speculation has centered on the United States or Israel as the most likely originators of the worm.