WASHINGTON (Reuters) - The United States sanctioned a Chinese cybersecurity company over an ambitious cyberattack that U.S. Treasury officials say could have killed people.

The Treasury said in a statement on Tuesday that the Chengdu-based Sichuan Silence Information Technology Company and one of its employees, Guan Tianfeng, deployed malicious software to more than 80,000 firewalls run by thousands of companies worldwide in April 2020.

The malicious software not only stole data, it was used to deploy ransomware, which paralyzes corporate networks by encrypting data. The statement said three dozen firewalls were protecting the systems of critical infrastructure companies and that, had the hacking not been thwarted or mitigated, the potential impact "could have resulted in serious injury or loss of human life."

In particular, the statement said that an energy company targeted in Sichuan Silence's hacking campaign was "actively involved in drilling" during the attack. Had it not been thwarted, the statement said, "it could have caused oil rigs to malfunction."

No further details about the incident were provided. Reuters could not immediately locate contact information for Guan.

Sichuan Silence has previously been accused of involvement in malicious digital activity. In 2021 Facebook and Instagram's parent company, Meta Platforms, alleged that the firm was linked to an online influence campaign that promoted claims of a phony biologist who said the United States was interfering in the search for the origins of COVID-19.

Beijing routinely denies being a party to hacking and other malicious cyber activity.