Hackers from China have attacked computer networks of global oil companies in a targeted campaign aimed at stealing confidential information, US computer security McAfee said today.

"Starting in November 2009, coordinated covert and targeted cyberattacks have been conducted against global oil, energy, and petrochemical companies," McAfee said in a report.

"We have identified the tools, techniques, and network activities used in these continuing attacks -- which we have dubbed Night Dragon -- as originating primarily in China," McAfee said.

It said that in addition to penetrating company computers, the hackers also targeted "individuals and executives in Kazakhstan, Taiwan, Greece, and the United States to acquire proprietary and highly confidential information."

McAfee did not identify any of the companies targeted by the hackers.

In January 2010, Google said it had been the victim of cyberattacks originating in China which included attempts to access the email accounts of Chinese human rights activists around the world.

China has denied involvement in the December 2009 cyberattacks which Google said also targeted more than 20 other companies.

According to US diplomatic files obtained and published by WikiLeaks, the United States believes that China's leadership directed the hacking campaign into computers of Google and Western governments.

In one cable, the US embassy in Beijing said it learned from "a Chinese contact" that the country's Politburo had led years of hacking into computers of the United States, its allies and Tibet's spiritual leader the Dalai Lama.