WASHINGTON (TNND) — Sen. Tim Scott, R-S.C., and Rep. French Hill, R-Ark., on Tuesday sent a letter to Treasury Secretary Janet Yellen demanding answers after Chinese hackers breached the U.S. Treasury Department.

The compromised third-party offering was a commercial remote services tool not listed in the marketplace for FedRAMP, the government’s cloud security compliance framework.

The cyberattack reported earlier this week reached into the Office of Foreign Assets Control and the Office of Financial Research, sections of the agency that oversee economic penalties against other nations and their citizens.

The US Treasury Department told lawmakers in a letter back in December that its documents and workstations were accessed by an external party in a security breach. It described the attack as "a major cybersecurity incident" and attributed it to a "China state-sponsored Advanced Persistent Threat actor.

Chinese government hackers breached a highly sensitive office in the Treasury Department that administers economic sanctions against countries and groups of individuals - one of the most potent tools possessed by the United States to achieve national security aims,