The hackers who infiltrated the Office of Personnel Management obtained personnel data and Social Security information on every federal employee, a government employee union said Thursday afternoon. This disclosure is an indication that the hack, which is believed to have begun more than a year ago, was much more damaging than government investigators have previously admitted.

J. David Cox, president of the American Federal of Government Employees, said in a letter to OPM Director Katherine Archuleta and obtained by the Associated Press that -- based on the OPM’s initial findings – military records, veterans’ status information, address, birth date, employment and pay history, health and life insurance, pension information, age, gender and race data were all compromised.

U.S. lawmakers and cybersecurity experts, including former Secretary of Homeland Security Michael Chertoff, have blamed the hack on hackers sponsored by the Chinese government, though Beijing has consistently denied responsibility.

Exactly how Cox came to his conclusion wasn’t immediately clear, though his and other federal unions have expressed frustration with how the OPM has reacted to the news that foreign hackers lurked within their computer systems for more than 12 months.

“They cannot even get through to a live human to answer their questions,” William Dougan, president of the National Federation of Federal Employees, which represents more than 110,000 employees, told the Hill Wednesday. “Federal employees deserve better than this.” 

Initial reports suggested that the records of 4 million government employees were affected. Then there came news that the Chinese were combing through the database of stolen records looking for individuals who might be sympathetic to Beijing, and thus willing to help the Chinese blackmail U.S. government workers.

The FBI suggested Wednesday that multiple hacker groups were behind the attack.