German claims he is certain
A German computer insecurity expert claims he can prove that the United States and Israel's Mossad wrote the Stuxnet worm to knock off Iran's nuclear program. Ralph Langner told the TED conference in the Southern California city of Long Beach that while Mossad was behind planting the worm the leading source was the United States.
The malicious code was crafted to stealthily take control of valves and rotors at an Iranian nuclear plant, according to Langner. He said that it was engineered by people who obviously had inside information and probably knew the shoe size of the operator. To get that level of detail you have to have an extremely detailed spy operation which could only have been developed by Mossad.
A terrifying aspect of Stuxnet, according to Langner, is that it is a generic attack that would work well in factories, power plants, or other operations plentiful in the United States. He said that it was a cyber weapon of mass destruction," Langner said.