The U.S. State Department disabled its entire unclassified email system on Friday in the face of a cyber attack, a senior official said. Technicians are working to repair the potential damage caused to the system by hackers and the State Department is expected to address the closure early this week once those repairs are made, the Associated Press reports. The official, who spoke on condition of anonymity, said unusual activity was first detected in the system in October, around the same time hackers targeted the White House computer network.