"We are getting very targeted Chinese attacks so it stretches credulity that these are not directed by government-related organisations," said the official.
The National Cyber Investigative Joint Task Force, a unit established in 2007 to tackle security, detected the attacks. The official stressed the hackers had accessed only the unclassified computer network, and not the more secure classified network.
"For a short period of time, they successfully breach a wall, and then you rebuild the wall . . . it is not as if they have continued access," said the official. "It is constant cat and mouse on this stuff."
Government, and corporate-sponsored, hackers are a growing concern. What makes them potentially more dangerous is that governments and corporations have deep pockets, can hire teams of specialists, and can afford to keep knocking away at a network, dumpster dive for documents, social engineer, maybe even work an employee or contractor to hand over data -- eventually they'll get in.
Last week, a U.K. IT security defense leader warned that U.K. interests were under steady attack. While last month, a Government Accountability Office's report found the federal government's IT security to be wanting.
When you have a motivated attacker targeting a disjointed, unfocused defender, it doesn't take a genius to deduce the outcome.