Chinese hacker targets Treasury Department in 'major incident.'

An actor affiliated with the Chinese government recently hacked the U.S. Treasury Department in a "major incident," officials announced on Monday.

In a letter obtained by FOX Business, the Treasury Department disclosed the incident to Senate Banking Committee leadership. Officials learned of the breach on Dec. 8.
 
The cybercriminal reportedly gained access to Treasury Department workstations and documents via a security key.

"Once Treasury was alerted by the service provider, we immediately contacted Cybersecurity and Infrastructure Security Agency (CISA) and have worked with law enforcement partners across the government to ascertain the impact of this incident," the spokesperson said. 

"The compromised BeyondTrust service has been taken offline and there is no evidence indicating the threat actor has continued access to Treasury systems or information."

The news came as the state-affiliated Chinese hackers continue an espionage campaign against the U.S. government. Last week, the White House said that Chinese officials accessed Americans' private texts and phone conversations through the targeting of a U.S. telecommunications company – the ninth telecom company to be affected by Chinese hacking.