Websites in China are being used to launch attacks on US Defence Department computer networks and other US agencies, according to reports in the Washington Post.
The newspaper cited four unnamed US government officials, who spoke separately about the attacks, which go back up to three years. Opinion was divided over whether the intrusions were organised by the Chinese government or by other hackers using Chinese sites to hide the origin of their attacks, the report said.
Hundreds of networks have been compromised, although classified networks have not been hit. Officials are said to be concerned that data from different networks could be brought together to provide useful intelligence.
“It's not just the Defence Department but a wide variety of networks that have been hit,” one official was quoted as saying. Other agencies hit included the State, Homeland Security and Energy departments, along with defence contractors.
“This is an ongoing, organised attempt to siphon off information from our unclassified systems,” the official said.
But the Post also quoted a more cautious assessment of the seriousness of the problem from another official. While there were "a large volume" of attacks, they were "not the biggest thing going on out there," he said.