In a December cyberattack, Chinese government hackers reportedly targeted the U.S. Treasury Department’s sanctions office.

Chinese government hackers have targeted the US Treasury’s highly sensitive sanctions office for some time December cyber attackaccording to the data.

according to The Washington Poststate-sponsored hackers have targeted the Office of Foreign Assets Control (OFAC), a government department that imposes economic and trade sanctions on countries and individuals, to obtain information about Chinese entities that the US government may consider imposing financial sanctions on.

The Chinese-backed hacking group that took over the US Treasury in December to gain access to employee workstations and unclassified documents also breached the Treasury Department’s Office of Financial Research and the Office of the Treasury Secretary, according to the report.

The cyberattack, described by the Treasury as a “major cybersecurity incident,” was discovered on Dec. 8 when BeyondTrust, a third-party software provider of identity management tools, alerted the agency to the cybersecurity incident.

The US Treasury Department did not immediately respond to questions from TechCrunch.