Chinese hackers broke into computer networks of the U.S. Personnel Management Office, the New York Times reports. The agency houses personal information for all federal employees.
During the attack, which occurred earlier this year, hackers sought to access the files of government workers who had applied for top-secret security clearances.
Senior U.S. officials confirmed the attack in March, saying it was blocked. They say that so far they've not "identified any loss of personally identifiable information."
It is still not clear how far the hackers penetrated the agency's systems.