WASHINGTON (AP) – A ransomware attack has paralyzed the networks of at least 200 U.S. companies. That’s according to a cybersecurity researcher whose company was responding to the incident. John Hammond of the security firm Huntress Labs says a major Russian-speaking ransomware syndicate appears to be behind the attack. He says the criminals in the REvil gang targeted a software supplier called Kaseya, using its network-management software as a conduit to spread the ransomware more widely. Other researchers agreed with Hammond’s assessment. It was not immediately clear how many Kaseya customers might be affected or who they might be.