Industrial computers infected by Stuxnet in Iran have been cleaned and returned to their units, a top official said on Sunday, following reports that the malware was mutating and wreaking havoc with equipment.
"The industrial computers infected by the Stuxnet virus have been cleaned," Mohsen Hatam, deputy industry minister, was quoted as saying on the state television's website.
Iranian media had said that Stuxnet had mutated and was wreaking havoc on computerised industrial equipment in Iran, with around 30,000 IP addresses infected.
But Hatam said that "all platforms have been cleaned and delivered to the industrial units."
"The virus infected these computers because they lacked high security firewalls," he added.
He said Stuxnet was "designed and despatched about a year ago to gather information from industrial computers."
Stuxnet, which was publicly identified in June, is a self-replicating malware found lurking on Siemens systems, mostly in India, Indonesia and Pakistan, but the heaviest infiltration appears to be in Iran, researchers say.
Analysts say Stuxnet may have been designed to target Iran's nuclear facilities, especially the Russian-built first atomic power plant in the southern city of Bushehr.
Officials have denied that Bushehr was among the addresses penetrated by the worm, but had acknowledged that some personal computers of the plant's personnel had been infected.
Iran's nuclear ambitions are at the heart of a conflict between Tehran and the West, which suspects the Islamic republic is seeking to develop atomic weapons under the cover of a civilian drive.
Tehran denies the allegation and is pressing on with its uranium enrichment programme -- the most controversial aspect of its nuclear activities -- despite four sets of UN Security Council sanctions.
Explore further: Social media sackings risk stifling journalistic expression