OT Cybersecurity: What Modern Manufacturers Must Secure in 2025

We have built entire industrial operations on computers talking to each other over networks that were never designed to be hostile. Somehow, attackers have learned how to turn that trust into free money or operational chaos on demand. Meanwhile, the IT and OT budgets responsible for defending these environments are often stretched thin, expected to protect everything with almost nothing.

That disconnect between expectation and reality is the core failure of OT cybersecurity.

When leadership asks, "What is an attack vector?", what they are really asking is how failure spreads. In OT environments, failure rarely starts with exotic exploits. It starts with trust that is too broad and access that never expires.

Flat networks, shared engineering credentials, vendor VPNs that were meant to be temporary, and Windows systems that "work fine" quietly expand the attack surface. Over time, these shortcuts become normal.

When something finally happens, it is labeled an incident. The uncomfortable truth is that the same conditions that enabled it are still present afterward.

Most manufacturing organizations believe they understand what assets exist on their OT networks. In practice, inventories are incomplete, outdated, or based on tribal knowledge. PLCs, HMIs, historians, engineering workstations, vendor laptops, and legacy servers communicate freely across zones.

When communication patterns change, no one can confidently say whether that change is expected or dangerous. OT incidents do not begin with alarms. They begin quietly, long before production is impacted.