A federal court in Hammond, Indiana, unsealed an indictment today charging Guan Tianfeng, a citizen of the People’s Republic of China (PRC) for his involvement in a conspiracy to hack indiscriminately into firewall devices worldwide in 2020. Guan and his co-conspirators worked at the offices of Sichuan Silence Information Technology Co. Ltd. to discover and exploit a previously-unknown vulnerability (an “0-day” vulnerability) in certain firewalls sold by U.K.-based Sophos Ltd. (Sophos) – an information technology company that develops and markets cybersecurity products. The malware that exploited the vulnerability discovered by Guan was designed to steal information from infected computers and to encrypt files on them if a victim attempted to remediate the infection. In total, Guan and his co-conspirators infected approximately 81,000 firewall devices worldwide, including a firewall device used by an agency of the United States.