From tripwire.com
OT networks often rely on Windows systems for various ICS applications including HMIs, historians, and data gateways. Beyond that, they also commonly rely on Windows systems to run associated IT-networks.
A successful ransomware deployment into either of these networks may prevent engineers from controlling plant operations and lead to an unplanned shutdown. This creates an immediate cost on the organization due to lost productivity. In the worst case, unplanned shutdowns may lead to physical failures that can damage equipment, potentially endangering lives in the process. The downtime from such an event could also span many months depending on the system. Specialized industrial equipment often cannot be replaced with existing components and take months to produce.