Volt Typhoon, a state-sponsored group of hackers based in China, has compromised the IT environments of multiple critical infrastructure organisations -- primarily in communications, energy, transportation systems and water and wastewater systems sectors -- in the US and its territories, the agencies said in a joint statement late on Wednesday. �� Cyber Attacks 2024: China-Backed Hackers 'Volt Typhoon' Access US Critical Infrastructure, Ready for Cyber Attack, Says Report.