Washington DC – A Chinese hacker with links to the state infiltrated the US Treasury Department’s systems, gaining access to employee workstations and some unclassified documents, officials revealed on Monday. The incident, which occurred in early December, was disclosed in a letter from the Treasury Department to lawmakers.

The breach, classified as a “major incident” by the US agency, prompted collaboration with the FBI and other entities to investigate the extent of the breach. The Chinese embassy in Washington DC dismissed the accusation as a “smear attack” lacking factual basis.

In the letter to lawmakers, the Treasury Department disclosed that the breach was facilitated by a third-party service provider, BeyondTrust, which provides remote technical support to its employees. The compromised service has been shut down, with no evidence indicating continued access to Treasury Department information by the hacker.

Collaborating with the FBI and other investigative bodies, the department is assessing the breach’s impact, attributing the hack to a China-based Advanced Persistent Threat (APT) actor. Despite the intrusion, officials confirmed that efforts are ongoing to safeguard data and prevent future breaches.

The department first learned of the hack on 8 December when BeyondTrust alerted them to suspicious activity on 2 December. The hacker managed to remotely access user workstations and certain unclassified documents within the Treasury Department during the breach.

Stating that the Treasury Department takes cybersecurity threats seriously, officials assured lawmakers of a forthcoming supplemental report on the incident within 30 days. The incident highlights ongoing concerns regarding Chinese espionage hackers’ activities, following previous breaches affecting various sectors in the US.