Officials sponsored by the Chinese government hacked into the Treasury Department in early December and accessed unclassified documents from its workstations, the department said in a letter to lawmakers on Monday.
The hackers stole keys from BeyondTrust, a third-party software service provider, and used them to disable security and gain access to Treasury workstations, according to a letter obtained by The Hill.
The agency is no longer using the compromised service and there is no evidence the hackers are still accessing Treasury information, the department noted.
“The Department of the Treasury takes all threats to our nation's systems and the data we hold very seriously,” the agency said in a statement.
“Over the past four years, Treasury has significantly strengthened our cyber defenses and will continue to work with private and public sector partners to protect the financial system from threat actors.”
Monday's letter said the agency is working with the Cybersecurity and Infrastructure Security Agency, the FBI, intelligence agencies and third-party investigators to investigate the incident.
He said he would provide additional information to lawmakers within 30 days. This is a requirement under current law for major cybersecurity incidents.
A spokesperson for Senate Banking Committee Ranking Member Tim Scott, R.S.C., said in a statement that the senator has sought clarification about the hack and is “monitoring the situation closely.” .
Rebecca Beitsch contributed to this report.
Updated at 5:43 p.m. ET
