Hackers linked to China’s Ministry of State Security have spent most of the last year infiltrating and moving freely through state government networks across the United States, according to a report by the cybersecurity firm Mandiant. Released on Tuesday, the report says that the hacking group known as APT41, whose members are already sought by the FBI for allegedly working on behalf of Beijing to conduct cyberattacks, began targeting at least six state governments starting last spring, and had not let up through the end of February. “This is a pretty unique switch,” Rufus Brown, a ??senior threat analyst at…