Oil giant Chevron was struck by the Stuxnet virus, a sophisticated cyber attack that tore through Iran's nuclear facilities and is believed to have been launched by the United States and Israel.

A Chevron spokesman told AFP Thursday that the virus had struck the oil giant in 2010 without causing any damage, confirming a report in the Wall Street Journal.

The virus was reportedly designed by US and Israeli intelligence to spy on and disrupt Iran's nuclear enrichment centrifuges, which Israel and the West believe is part of a secret nuclear weapons program, charges denied by Tehran.

Stuxnet -- which was designed to attack computer systems designed by German industrial giant Siemens for managing water supplies, oil rigs, power plants and other critical infrastructure -- has turned up in other countries.

Analysts and former US military officers have touted cyber attacks as a more effective weapon against Iran's nuclear ambitions than bombing raids, which they say would carry big risks without causing permanent damage to the program.

But Chevron officials said the virus spread beyond Washington's control.

"I don't think the US government even realized how far (the virus) had spread," Mark Koelmel, who oversees earth-science research and development at Chevron, told the Wall Street Journal.

"I think the downside of what they did is going to be far worse than what they actually accomplished," he added.

Neither the United States nor Israel has ever officially acknowledged the Stuxnet program.

Google service disrupted in China
San Francisco (AFP) Nov 9, 2012 - Google on Friday reported unexplained disruptions to its service in China.

"We've checked and there is nothing wrong on our end," a Google spokeswoman told AFP.

An online tool that tracks outages or disruptions to the California-based Internet giant's services showed online traffic in China plummet mid-day.

The disruption followed reports that Chinese Internet users have evaded censors to take pot shots at President Hu Jintao's assessment of his performance in a farewell speech.

Hu launched a week-long Communist Party congress in Beijing on Thursday with a speech that touted his political leadership, but also warned in stark terms of worsening problems such as corruption that threaten the party's legitimacy.

Users of the country's hugely popular microblogging sites -- the only major forum for relatively open expression in the tightly-controlled country -- reacted with cynicism.

The GreatFire.org website, which early last year began tracking Internet censorship in China, reported Friday that testing showed an array of Google websites were blocked there including search, email, and maps.

"This means that none of these websites, including Google Search, currently work in China, unless you have a VPN or other circumvention tool," according to a blog on the site, which monitors China's censorship online.

Beijing has denied involvement in the cyberattacks on the California-based firm, calling such accusations "groundless."

Google on Friday confirmed a sharp drop in access to its products in China, noting that it was the middle of the night there and that a clearer picture of the situation should be available as the day got underway.

Chinese censors last month blocked online searches related to the New York Times as well as the newspaper's websites after it published an investigation on the wealth of the Chinese premier's family.

China operates a huge system of Internet control and censorship dubbed the Great Firewall of China, aimed at snuffing out information or comments that the government considers a threat to its authority.

In early 2010, the Google said it suffered cyber-attacks from China-based parties apparently intent on hacking into the Gmail accounts of Chinese rights activists.

The resulting row caused tensions to spike between China and the United States and ended with Google reducing its presence in the Chinese market.