Microsoft Corp. said it’s found malicious activity by a Chinese-state sponsored hacking group that has stealthily gained access into critical infrastructure organizations in Guam and elsewhere in the US, with the likely aim of disrupting critical communications in the event of a crisis. In a report published Wednesday, Microsoft said the group, named Volt Typhoon, had been active since mid-2021, targeting organizations that span manufacturing, construction, maritime, government, information technology and education. Microsoft said it has “directly notified targeted or compromised customers" and had accessed, with “moderate confidence," that the activity was in preparation to upend communications during a future...