Malware affecting industrial control systems (ICS) has the potential to disrupt key industries underpinning modern society, warned a report released Wednesday by the cybersecurity research website Comparitech.

Internet-exposed ICS devices are a primary target for threat actors, particularly those running legacy protocols such as Modbus, according to researcher Justin Schamotta.

Schamotta identified 179 internet-exposed ICS devices in his report. “One ICS device we identified as being part of a national railway network,” he wrote. “Railways use ICS devices to help with everything from train routing to signaling. The exposure of such devices could present a serious operational and safety risk.”

“Two other devices (one in Asia and one in Europe) formed part of their respective country’s national power grid infrastructure,” he added. “In the energy supply sector, ICS devices can be used to monitor consumption and control electrical distribution.”

Schamotta noted that the United States had the most exposed industrial control devices, 57, followed by Sweden with 22 and Turkey with 19.