The Stuxnet computer worm that infiltrated industrial systems in Iran this fall may have been specifically designed to attack the country's nuclear program, potentially crippling centrifuges used to enrich uranium gas, according to new research.

In a blog post Friday, a Stuxnet researcher at Symantec wrote that the software firm had concluded that the worm targets industrial systems with high frequency "converter drives" from two specific vendors, including one in Iran.