The Treasury Department has announced sanctions in connection with a massive Chinese hack of American telecommunications companies and a breach of its own computer network.

The Treasury Department’s Office of Foreign Assets Control (OFAC) announced on Friday that it had sanctioned a China-based cybersecurity company, known as Sichuan Juxinhe Network Technology, which it says is directly linked to the China-backed Salt Typhoon hacking group.

The U.S. Treasury Department on Friday imposed sanctions on alleged hacker Yin Kechen and cybersecurity company Sichuan Juxinhe Network Technology Co., accusing both of being involved in a series of hacks against American telecom companies.