China blamed by US for Treasury Department hack

Unclassified documents were stolen after a hack earlier this month, according to a letter sent by Treasury to Congress.

Chinese state-sponsored hackers were able to steal unclassified documents from United States Treasury workstations earlier this month, the US Treasury Department has said.

The department said on Monday that the hackers were able to compromise a third-party cybersecurity service provider and gain access to the documents in what it described as a “major incident”.

“[The hackers] gained access to a key used by the vendor to secure a cloud-based service used to remotely provide technical support for Treasury Departmental Offices (DO) end users,” a letter sent by the US Treasury Department to Congress said. “With access to the stolen key, the threat actor was able to override the service’s security, remotely access certain Treasury DO user workstations, and access certain unclassified documents maintained by those users.”

A statement from the Treasury said that the department “takes very seriously all threats against our systems, and the data it holds”.

The Treasury Department was alerted to the hack by the cybersecurity provider, BeyondTrust on December 8. The department says it is working with the US Cybersecurity and Infrastructure Security Agency (CISA) and the FBI to assess the impact of the hack.