US was 'key player in cyber-attacks on Iran's nuclear programme'

The US was the principal player in the most sophisticated cyber-attack ever known and has been orchestrating a campaign against Irandesigned to undermine the country's nuclear programme, it has been claimed.

According to anonymous senior administration sources, quoted in the New York Times, President Barack Obama decided to speed up an initiative launched by his predecessor, George W Bush, codenamed Olympic Games, which aimed to use computer viruses to attack Tehran's uranium-enrichment programme.

The disclosures about Obama's role in the cyberwar against Iran appear to show beyond doubt that the US, with the help of Israel, was behind the Stuxnet virus, which sent some of Iran's centrifuge machines – used to enrich uranium – spinning out of control. The revelation will raise questions about whether Washington was also behind the Flamer virus discovered by experts last week.

Flamer also targeted Iran, though its main aim was to spy on the country's oil industry. It is believed to have downloaded vast amounts of information over two years and had technical capabilities never seen before.

The revelations about US involvement in cyberwar may be seized upon by China and Russia, which are regularly accused by Washington of cyber espionage and theft.

The depiction of Obama's hands-on role in cyber attacks follows the highly political disclosure in an election year that the president had taken a personal role in approving terrorist targets for US drone strikes. The revelations on Iran appear designed to neutralise Republican accusations that he has been weak over the issue of Iran's nuclear programme.

According to the New York Times, Obama took the decision to accelerate the pace of computer sabotage against Tehran in 2010, even after details about one of the cyber weapons developed to attack Iran, the Stuxnet worm, accidentally leaked on to the internet. It had been designed to target Iran's Natanz nuclear plant.

At a meeting in the White House situation room within days of the Stuxnet leak, Obama asked his advisers, including Leon Panetta, the head of the CIA, whether the effort should be wound up because it had been compromised.

According to sources in the room at the time, Obama asked: "Should we shut this thing down?", before opting instead to push ahead with the attacks. The Natanz plant was hit twice more by versions of the worm, which damaged up to 1,000 high-speed centrifuges then enriching uranium.

The revelation of Obama's involvement in ordering cyber-attacks on Iran in a joint programme involving Israel follows the disclosure that Iran had recently been hit by the Flamer virus, thought to be 20 to 40 times larger than Stuxnet.

According to the latest analysis of Flamer, it had a bluetooth capability never seen before in a computer worm. The computer security firm Symantec said any laptop infected with Flamer would search for other bluetooth-enabled devices, sucking up information that might include mobile phone numbers. This would help the attacker "identify the victim's social and professional circles".

The Kaspersky Lab, a Russian-based computer security firm that has studied Stuxnet and Flame, said the first Stuxnet attack on Iran took place around June 2009, but its existence did not emerge until almost a year later, appearing to fit precisely the timeline proposed by the New York Times' sources. Some experts have said there are sufficient similarities between the worms to suggest they have the same source.

Last year the US deputy defence secretary, William Lynn, declined to reveal whether the US was involved in the development of Stuxnet. "This is not something that we're going to be able to answer at this point," he said.

The timing of the disclosure to the New York Times's David E Sanger, who boasts of access to Obama and his closest officials, is particularly significant. In recent weeks, the Republican candidate, Mitt Romney, has tried to portray the Obama administration as weak and muddled on foreign policy, most recently over the crisis in Syria. Recent sympathetic media disclosures appear to have been designed to counter this suggestion.

Stuxnet was launched in 2006 after President Bush was advised that a cyber weapon might be more effective than sabotage – the CIA had introduced faulty materials into Iran's nuclear procurement networks.

The goal then was to secretly access Natanz's industrial computer controls, which had been designed by the German company Siemens, to acquire a blueprint of how it worked.

That achieved, a joint US-Israeli operation set about building a worm to attack the plant and make its centrifuges run out of control. As was suggested at the time, Stuxnet appears to have been introduced into the Iranian plant with contaminated computer drives.

"That was our holy grail," one of the architects of the plan said, referring to how the plant was physically accessed. "It turns out there is always an idiot around who doesn't think much about the thumb drive in their hand."

US sources quoted blame Israel for the eventual discovery of the worm. They said the Israeli partners modified Stuxnet and made a programming error that caused it to escape and replicate in cyberspace.

The disclosures throw fresh light on the rapid development of US cyberwarfare capability and reveal its willingness to use cyber weapons offensively to achieve policies.