In announcing a possible exit from China last week, Google did not specify how the accounts with its Gmail e-mail service were hacked into or by whom. Information since then has trickled out.
The Foreign Correspondents' Club of China sent an e-mail Monday to its members warning that reporters in at least two news bureaus in Beijing said their Gmail accounts had been broken into, with their e-mails surreptitiously forwarded to unfamiliar accounts.
Although the warning did not name the organizations, one of the accounts belonged to an Associated Press journalist.
John Daniszewski, senior managing editor for international news at the news cooperative in New York, deplored the breach and said the AP will be investigating to determine if any vital information was compromised.
The foreign correspondents' club asked its members to be vigilant in protecting their e-mail accounts and computers from attack.
"We remind all members that journalists in China have been particular targets of hacker attacks in the last two years," the club's message read. "Please be very careful what you click on, and run virus checks regularly."
Google's announcement Tuesday that it might quit the huge Chinese market shocked the international business community and cheered many free-speech advocates. Google said a sophisticated attack in December from China targeted the Mountain View, California-based company's infrastructure and at least 20 other major companies from the Internet, financial services, technology, media and chemical industries.
Google said only two e-mail accounts were infiltrated in the attacks, with basic information such as subject lines and the dates that the individual accounts were created accessed. In its investigation, Google said it found that dozens of accounts of human rights advocates in China, the U.S. and Europe were routinely accessed by third parties, not due to a security breach at Google, but through viruses and spy software secretly placed on the users' computers.
The tactics used against the journalists are similar to those described by one human rights activist. After Google's announcement, Beijing law professor and human-rights lawyer Teng Biao wrote on his blog that someone broke into his Gmail account and forwarded e-mails to another account. The attack made use of a service that Gmail and other Web-based e-mail services offer, allowing users to set e-mail addresses to which their mail can be forwarded automatically.
Another activist said she was notified by David Drummond, Google's top lawyer, on Jan. 7 about an intrusion into her account. Tenzin Seldon, a Tibetan rights activist and sophomore at Stanford University, said she allowed her laptop to be inspected by Google's security experts, who found no viruses on the machine.
China-based international correspondents have seen their e-mail accounts hit by periodic waves of cyberattacks and snooping from undetermined sources over the past two years. The AP, Agence France-Presse, Dow Jones, Reuters and other news organizations were targeted in September in an attack in which viruses were implanted in ordinary looking e-mails.
The e-mails, which appeared to be from an editor of an English-language paper in Singapore, bore an attachment that once opened would install malware malicious software on computers, said a report late last year by computer security experts McAfee Inc.