WASHINGTON (WJZ) — The biggest data breach in government history just got bigger. An employee union claims every single federal worker was hacked, including hundreds of thousands of people in Maryland.

Derek Valcourt with the sensitive information at risk for millions.

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The numbers could be staggering. The data breach affecting current and former federal employees–including some of those retired.

The federal government originally warned the biggest cyber attack on the U.S. government ever affected some four million federal employees.

But in a letter criticizing the government, the president of the union representing federal workers now says based on the sketchy information the government has provided, they believe that hackers are now in possession of all personnel data for every federal employee.

“I don’t know. You can’t trust anything these days,” said Al Salters, federal employee.

Salters works at the Social Security Administration in Woodlawn–one of as many as 300,000 current federal workers living in Maryland.

The American Federation of Government Employees says the compromised data includes social security numbers, addresses, dates of birth, insurance and pension information, military records and even job and pay history.

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The union letter also chastises the government, saying social security numbers were not encrypted, calling that a cyber security failure that is absolutely indefensible and outrageous.

“Huge mistake,” said Gary Buclous, Infoworks Technologies.

Computer expert Gary Buclous specializes in cyber security.

“Not to encrypt things these days… insurance companies are forcing people like me to encrypt everything I have these days,” he said. “So if the federal government is not encrypting their data, it’s a national security breach. It’s very scary.”

“Not a thing you can do about it right now until they find a way to stop it,” said Salters.

For now, federal employees say they can only monitor their credit and hope nothing happens.

The Office of Personnel Management has offered affected employees 18 months of credit monitoring services for free. Union officials say those government workers deserve free credit monitoring for life.

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Some U.S. officials believe the hackers are from China, but the Chinese government has denied involvement.