U.S. Treasury Secretary Janet Yellen met virtually on Monday with Chinese Vice Premier He Lifeng and raised concerns about "malicious cyber activity" carried out by Chinese state-sponsored actors, the Treasury Department said in a statement.

US Treasury Secretary Janet Yellen told China’s Vice Premier He Lifeng of her “serious concern” regarding “malicious cyber activity” a week after the US said Chinese state-sponsored hackers had breached the Treasury Department’s computer networks.

Liu Pengyu, a spokesperson for the Chinese Embassy in Washington, D.C., denied the U.S. government’s attribution of the cyberattack to the Chinese government, arguing that the United States did not present evidence of its claims.

Threat actors entered Treasury Department systems through BeyondTrust. The breach may be related to the Salt Typhoon attacks.