In May, security experts discovered one of the most widespread malware infections in history. Now, they’re warning businesses and consumers that it’s even worse than their first assessment. The VPNFilter malware poses a threat to small businesses and requires immediate attention from anyone who hasn’t taken action against it.

A week ago, leading cyber threat intelligence team Cisco Talos reported that no less than 500,000 IoT devices in up to 54 countries were infected by new malware called VPNFilter. An earlier version, believed to be launched by a nation-state, targeted Ukraine.