Flame virus most powerful espionage tool ever, UN warns Evidence suggest that the virus, dubbed Flame, may have been built on behalf of the same nation or nations that commissioned the Stuxnet worm that attacked Iran's nuclear program in 2010, according to Kaspersky Lab, the Russian cyber security software maker that took credit for discovering the infections. "I think it is a much more serious threat than Stuxnet," Mr Obiso said. Unlike the Stuxnet virus that was previously used to disrupt Iranian systems, Flame does not disrupt or terminate systems. Iran, whose nuclear facilities and oil ministry have previously been the target of virus attacks, accuses the US and Israel of trying to sabotage its programme. It considers Iran to be the greatest threat to its survival.