Beijing - Chinese hackers in March gained access to US government computer networks containing data on federal employees, the New York Times reported Wednesday, citing government sources.
It was not clear how far into the database the hackers reached before federal authorities detected the threat and blocked them from the network, the report said.
The attack seemed to target files on employees who had applied for top-security clearance, some tens of thousands of people.
A Department of Homeland Security official confirmed the attack to the newspaper, saying that "at this time" it had not "identified any loss of personally identifiable information."
The hacked Office of Personnel Management systems contain information including security-clearance applicants' foreign contacts, previous employment and other personal information.