Unclassified State Department computer system hacked, email shut down

The State Department has taken the unprecedented step of shutting down its entire unclassified email system as technicians repair possible damage from a hacker attack.

A senior department official said Sunday that "activity of concern" was detected in the system around the same time as a previously reported incident that targeted the White House computer network. That incident was made public in late October, but there was no indication then that the State Department had been affected.

The official said the State Department shut down the email late on Friday as part of a scheduled outage of some of its Internet-linked systems to make security improvements to its main unclassified computer network. The official was not authorized to speak about the matter by name and spoke on condition of anonymity.