Microsoft warned on Wednesday that it has uncovered “stealthy and targeted malicious activity” by a state-sponsored actor in China aimed at disrupting “critical infrastructure organizations” in the United States. The Redmond, Wash.-based tech giant said in a security blog post that the “Volt Typhoon” campaign has been active since mid-2021. Targeted organizations in Guam and elsewhere in the U.S. include communications, manufacturing, utility, transportation, construction, maritime, government, information technology, and education sectors. Microsoft said Volt Typhoon “could disrupt critical communications infrastructure between the United States and Asia region during future crises.” The company added that behavior it has observed suggests hackers intend to perform espionage and maintain access without being detected for as long as possible.