NY Times says Chinese hacked paper's computers

China has been accused by the U.S., other foreign governments and computer security experts of mounting a widespread, aggressive cyber-spying campaign for several years, trying to steal classified information and corporate secrets and to intimidate critics. Foreign reporters and news media, including The Associated Press, have been among the targets of attacks intended to uncover the identities of sources for news stories and to stifle critical reports about the Chinese government.

"Attacks on journalists based in China are increasingly aggressive, disruptive and sophisticated," said Greg Walton, a cyber-security researcher who has tracked Chinese hacking campaigns. China's cyber-spying efforts have excelled in part because of the government's "willingness to ignore international norms relating to civil society and media organizations," he said.

The Times reported that executives became concerned just before the publication of the Wen investigation after learning that Chinese officials had warned of unspecified consequences. Soon after the Oct. 25 publication, AT&T, which monitors the Times' computer networks, notified the company about activity consistent with a hacking attack, the report said.

After months of investigation by the computer security firm Mandiant, experts are still unsure how the hackers initially infiltrated the Times' computer systems, the report said.