China has slammed a decision by the U.S. Treasury to sanction a Beijing-based cybersecurity company for its alleged role in multiple hacking incidents targeting critical U.S. infrastructure, while the Chinese cyber security agency complained Monday of attacks on Chinese networks.

Chinese government hackers breached the U.S. Treasury Department. Among other things, the hackers breached the office that administers economic sanctions against countries and groups of individuals. The hack also compromised the Treasury Department’s Office of Financial Research.

China slammed the U.S. Monday for sanctioning a Beijing-based cybersecurity firm allegedly behind a botnet targeting American infrastructure, accusing Washington of “using the issue of cybersecurity to vilify and smear China.