A hacker group known as Flax Typhoon was able to infect hundreds of thousands of devices around the world, authorities said. China has denied any involvement in the malicious botnet.

The FBI said on Wednesday that it had disrupted a Chinese hacking group nicknamed “Flax Typhoon” that targeted critical infrastructure in the United States.

The Flax Typhoon hackers installed malicious software on thousands of computers and other internet-connected devices including cameras, video recorders and routers.

This created a botnet — a massive network of infected computers.

Universities, government agencies, telecommunications providers, media organizations and NGOs were among the targets, the FBI said.