The malicious code, called Stuxnet, was designed to go after several “high-value targets,” said Liam O Murchu, manager of security response operations at Symantec Corp. But both O Murchu and U.S. government experts say there’s no proof it was developed to target nuclear plants in Iran, despite recent speculation from some researchers…

Symantec’s analysis of the code, O Murchu said, shows that nearly 60 percent of the computers infected with Stuxnet are in Iran. An additional 18 percent are in Indonesia. Less than 2 percent are in the U.S.

“This would not be easy for a normal group to put together,” said O Murchu. He said “it was either a well-funded private entity” or it “was a government agency or state sponsored project” created by people familiar with industrial control systems.