The US Navy's biggest customer on the island of Guam, the GPA power utility, has been compromised by Chinese hackers known as Volt Typhoon. The infiltration was so discreet that it was only detected through small anomalies in login patterns. The group is suspected of being involved in a larger campaign to disrupt critical infrastructure and enable "destructive attacks" on US citizens in the event of a major conflict. According to Jen Easterly, Director of the Cybersecurity and Infrastructure Security Agency (CISA), Chinese threat actors like Volt Typhoon are building capacity to cut off telecommunications, disrupt pipelines, pollute water facilities, and cripple transportation.
https://www.techradar.com/pro/security/guams-critical-infrastructure-is-under-attack-and-volt-typhoon-is-the-top-suspect