A company in Australia came under a cyberattack from China that was intense enough to slow traffic on part of the country's second-largest broadband network, company officials said Thursday.
Among companies affected were Australian Associated Press, the national news agency, and the Australian branch of Rupert Murdoch's News Ltd., but they were not the targets, said the telecommunications company Optus.
Attackers in China flooded an international network link to one of Optus' large commercial clients in Australia in what is known as a denial-of-service attack, the company said. This caused congestion that significantly slowed Internet and e-mail links to other customers on that link, including AAP and News.
Optus declined to identify the company targeted, citing commercial confidentiality. News Ltd.'s The Australian newspaper reported that it was a multinational financial institution, but had no further details. Optus also declined to say how many customers were affected.
The attack was blocked after about 2 1/2 hours.
Denial-of-service attacks involve a flood of computers all trying to connect to a single site at the same time, overwhelming the server that handles the traffic.
Cyberattacks linked to China have gained more attention since Google Inc. accused Chinese hackers in January of trying to plunder its software coding and of hijacking the Gmail accounts of human rights activists protesting Beijing's policies.
Early this month, a foreign journalists' organization in China had its Web site disrupted by attackers in China and the United States — the latest in a string of such cases.
Yahoo e-mail accounts belonging to foreign journalists in China have also apparently been hacked in recent weeks, and at least one rights group focusing on China says it has been hit by denial-of-service attacks.
Tony Gillies, editor-in-chief of AAP, said the company's e-mail and Internet services were slowed by the attack but delivery of its news services was not affected significantly.
"Our system protocols meant that we were OK," Gillies said. "We can't find any evidence that we were being targeted."
Optus is Australia's second-largest Internet Service Provider.