office of personnel management

Chinese hackers have caused a massive data breach in U.S. government computer networks, placing the entire federal workforce at risk.

Data from the Office of Personnel Management, which is essentially the human resources department for the federal government, as well as the Interior Department have been accessed by foreign hackers, the Department of Homeland Security confirmed in a statement as reported by the Associated Press.

The FBI is investigating how the data breach happened, but so far authorities believe the hackers were based in China.

The revelation brought about a stern rebuke from Maine Republican Sen. Susan Collins, who expressed dismay at “yet another indication of a foreign power” probing into federal networks and trying to get data on people with security clearances.

However, the Chinese Embassy in Washington struck back at the accusations, calling them “counterproductive.” The embassy noted that cyberattacks are notoriously hard to track and thus identifying a source is not easy, and finding the hackers will require international cooperation.

The AP quoted an anonymous official who said that the data could affect potentially every federal agency, and a critical question is whether any information from intelligence agency employees were stolen.

OPM conducts about 90 percent of all federal background investigations, making its data particularly sensitive for federal workers and the government itself.

In response to the cyberattack, the agency will offer identify theft insurance and credit monitoring for 18 months to those who were believed to be affected by the hack.