The White House has been attacked by hackers from China.
A senior US official told the Financial Times that the hackers attacked the network on multiple occasions, and obtained emails between government officials.
The official reported that the attackers managed to penetrate the White House system for brief periods that allowed them to steal information before US government experts patched the system.
They were detected by the National Cyber Investigative Joint Task Force, though the official stressed the hackers had accessed only the unclassified computer network and not the more secure classified network.
The official said: “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. It is constant cat and mouse on this stuff.”
Sami Saydjari, head of the Cyber Defence Agency, said: “This underscores the need for president-elect Obama to take leadership in the cyber space race that is well under way.”