WASHINGTON — Hackers working on behalf of the Chinese government broke into the computer networks of at least six state governments in the United States over the past year, according to a report released Tuesday by a private cybersecurity firm. Mandiant’s report does not identify the compromised states, nor does it offer a motive for the intrusions that began last May. But the Chinese group blamed for the breaches, APT41, has been known to launch hacking operations for both old-fashioned espionage purposes and financial gain. “While the ongoing crisis in Ukraine has rightly drawn world attention and the potential for...