SAN FRANCISCO -- Researchers at Symantec have uncovered a
version of the Stuxnet computer virus that was used to attack
Iran's nuclear program in November 2007, two years earlier than
previously thought. Planning for the cyber weapon, the first
publicly known example of a virus being used to attack
industrial machinery, began at least as early as 2005, according
to an 18-page report that the Mountain View security software
company published on Tuesday. Stuxnet, which is widely believed
to have been developed by the United States and Israel, was
uncovered in 2010 after it was used to attack a uranium
enrichment facility at Natanz, Iran. That facility has been the
subject of intense scrutiny by the United States, Israel and
allies, who charge that Iran is trying to build a nuclear bomb.
Symantec said its researchers had uncovered a piece of code,
which they called "Stuxnet 0.5," among the thousands of versions
of the virus that they had recovered from infected machines.
Stuxnet 0.5 was designed to attack the Na