As a CTO or CIO, you are probably already in the process of planning a KSC/NIS2 deployment for your enterprise infrastructure (IT). There are conversations around SIEM systems, EDR and supply chain policies. However, there is an area that has been off the radar of IT departments for years that the new regulations are putting at the heart of: Operational Technology (OT). It’s an environment where a cyberattack no longer means “just” losing data, but physically halting production, threatening human safety and paralyzing critical services.
For companies in the industrial, energy or transportation sectors, KSC/NIS2 is a revolution that forces IT and engineering departments to take joint responsibility for ICS, SCADA and PLC systems. This challenge is fundamentally different from anything you’ve faced in the IT world. It requires not only different tools, but more importantly, a different mindset that prioritizes uninterrupted production continuity.
Shortcuts
- What exactly is OT security and why does KSC/NIS2 emphasize it so strongly?
- Why is the traditional approach to IT security ineffective in OT networks?
- What are the biggest risks of integrating IT and OT networks?
- What is a KSC/NIS2 compliant OT security audit?
- What is the Purdue model and why is it crucial for OT network segmentation?
- How to conduct a strategic risk assessment for manufacturing processes?
- How to test safety in OT environments without stopping production?
- How to prepare an incident response (IR) plan specific to OT?
- Differences in Incident Response: IT vs. OT
- Why do you need a specialized partner to implement OT security?
What exactly is OT security and why does KSC/NIS2 emphasize it so strongly?
Operational Technology (OT) is a collection of hardware and software systems that monitor and control physical processes. We’re talking about industrial control systems (ICS), supervisory control and data acquisition (SCADA) systems, and programmable logic controllers (PLCs). In short, this is the technology that “turns” machinery in a factory, manages flow in a pipeline or controls a catenary network.
KSC/NIS2 puts such a strong emphasis on this area because it applies to key entities whose disruption has a direct impact on the economy and society. The legislator understands perfectly well that an attack on OT systems at a power plant, a sewage treatment plant or a food manufacturer is much more dangerous than an attack on a website.
That’s why the new regulations include the protection of OT/ICS systems, which for many organizations means having to build security competencies in this area practically from scratch. OT security is becoming synonymous with ensuring operational continuity, which is one of the main pillars of KSC/NIS2.
📚 Read the complete guide: NIS2: Complete guide to the NIS2 Directive - obligations, penalties, deadlines
Why is the traditional approach to IT security ineffective in OT networks?
As an IT manager, you may think, “since I have EDR, firewall and procedures, I’ll just extend them to the production area.” This is a disastrous mistake. The OT environment operates under completely different rules than IT. Trying to apply IT standards 1:1 is not only ineffective, but can be downright dangerous to the production process.
In IT, the priority is data confidentiality (Confidentiality). In OT, availability (Availability) and integrity (Integrity) are the absolute king. You can’t “momentarily” turn off a PLC to upload a safety patch if that PLC is managing the operation of a chemical reactor or a smelter furnace. OT systems are designed to run continuously for 20 years, not for weekly updates.
Moreover, standard IT tools such as vulnerability scanners work aggressively. Running a port scan on an IT network will, at most, momentarily slow down a server. Running the same scan on an OT network can “hang” an old PLC and bring an entire production line to an uncontrolled halt.
What are the biggest risks of integrating IT and OT networks?
Historically, OT networks were secure because they were physically isolated (“air-gapped”). They had no connection to the Internet or to the office network. That world no longer exists. In the pursuit of efficiency, data analytics and Industry 4.0, companies massively connected their IT (office) networks to OT (production) networks.
It is this integration that has created a “highway” for cyber threats. Today, the most common attack scenario is one in which an attacker gets into the IT network (e.g., through phishing) and then, taking advantage of the lack of proper separation, moves laterally into the OT network.
The result? A ransomware attack, which in an IT network is “just” a business problem (encrypted files), in an OT network becomes an operational crisis. Encryption of an HMI station or SCADA server means an immediate halt in production, financial losses running into millions per hour and the risk of physical damage to machines.
What is a KSC/NIS2 compliant OT security audit?
The first step to securing OT is to understand what you actually have and what the risks are. However, an OT security audit, which is required by NSC/NIS2, is quite different from an IT audit. Partners such as nFlo perform dedicated NIS2 compliance assessments for OT/ICS and compliance audits for a key industry standard - IEC 62443.
Such an audit does not involve active scanning. Passive vulnerability assessment is key. Specialized probes “listen” to OT network traffic, identifying devices (PLC, HMI), protocols (e.g., Modbus, Profinet) and known vulnerabilities, all without sending a single packet that could disrupt production.
The audit also includes an analysis of the configuration of operator stations, SCADA servers and the controllers themselves. It is also crucial to check procedures - whether there is an OT security policy, how remote access by service technicians is managed, what the upgrade process is like (if it is possible at all).
What is the Purdue model and why is it crucial for OT network segmentation?
If there is one technical concept that you as CTO/CIO need to implement in OT, it is network segmentation based on the Purdue model. This is the absolute foundation of OT security that directly addresses the risk of an attack jumping from IT to OT.
The Purdue model is a logical architecture that divides the infrastructure into hierarchical levels - from the sensors and machines at the “bottom” (Level 0/1), to the control systems (Level 2), production management (Level 3) and the IT corporate network (Level 4/5). The whole philosophy is to create security zones and rigorously control communications between them.
In practice, this means “designing an OT security architecture” in which the IT network cannot communicate directly with PLCs. Traffic must pass through a demilitarized zone (DMZ), where it is filtered by specialized firewalls (Industrial Firewalls). Implementing this model is the most important step in building resilience.
How to conduct a strategic risk assessment for manufacturing processes?
KSC/NIS2 is based on a risk-based approach. In the OT world, this risk is not measured by the value of the data on the server, but by the cost of stopping the production process. Therefore, as CTO/CIO, you need to initiate a strategic risk assessment for production processes.
This means that instead of asking “what is the risk to this server?”, you need to ask: “What is the financial and operational loss if this production line stands for 4 hours? And for 24 hours?”. This completely changes priorities.
Such an assessment, done in conjunction with manufacturing and engineering, identifies the most critical OT assets. It may turn out that the most important asset is not a new SCADA server, but an old, unpatched PLC that no one has moved in 15 years, but which controls a key machine. That’s where the first budget for risk mitigation must go.
How to test safety in OT environments without stopping production?
This is one of the most common questions and biggest concerns of technical directors. We want to test for safety, but we can’t risk downtime. The answer lies in specialized, passive and safe testing methods.
As mentioned, the basis is a passive vulnerability assessment - that is, monitoring network traffic to find weaknesses, without active intervention. The second element is a review of the configuration of PLCs, HMIs and SCADA systems. These are analyzed for good security practices (e.g., whether default passwords have been changed).
Only in the third place are secure penetration tests of OT/ICS systems performed. They are never done “live” in production. They are carried out in close collaboration with engineers, often in a controlled test environment (lab) or during a scheduled maintenance window.
How to prepare an incident response (IR) plan specific to OT?
Having an incident response plan is a hard requirement of KSC/NIS2. However, an IR plan for IT is useless in an OT environment. In IT, the first response to a ransomware attack is to “cut off the server from the network.” Applying the same logic in OT and suddenly cutting off the PLC can lead to physical damage to machines or danger to people.
An OT incident response plan must be developed from scratch. It must define who makes decisions to stop the production process in a safe and controlled manner. It must include process engineers and machine operators, not just IT specialists.
Therefore, it is crucial not only to develop these plans, but also to test them regularly through tabletop exercises. Simulating a “ransomware attack on the production line” allows you to practice communication and decision-making between IT, OT and management under safe conditions.
Differences in Incident Response: IT vs. OT
Understanding the fundamental differences in priorities is key to an effective KSC/NIS2-compliant IR plan.
| Aspect | Responding in the IT World (Traditional) | Responding in an OT World (KSC/NIS2 Requirement) |
|---|---|---|
| Main Priority | Data Confidentiality. Stopping information leakage. | Physical security and continuity. Protecting people, machines and ensuring the safe state of the process. |
| First Response | Insulation. “Cut off the server from the network” to stop the spread of the attack. | Process control. “Maintain stability” or “carry out a safe, controlled stop” of the physical process. |
| Key Team | IT/Security team, lawyers, PR. | IT/Security team + Process Engineers, Machine Operators, Maintenance Department, Plant Manager. |
| Restore | Restore data from backup, analyze logs. | PLC/DCS integrity verification, machine calibration, safe restart of physical process. |
| Partner Support | Malware analysis support, computer forensics. | Expert support in OT incident handling, knowledge of industry protocols and OT security procedures. |
Why do you need a specialized partner to implement OT security?
As CTO/CIO, you know that your internal IT team are experts in enterprise systems. Maintenance and engineers are experts in manufacturing processes. The problem is that neither group is an expert in OT security. It’s a highly niche field, requiring a simultaneous understanding of IT-level cyber security and the specifics of industrial protocols and physical risk.
Trying to implement KSC/NIS2 in the OT area by internal forces is extremely risky. You can accidentally stop production or implement solutions that will not be effective. That’s why you need a partner that bridges these two worlds.
A partner like nFlo has a dedicated “CyberSec - OT” service pillar. This is a team that understands IEC 62443, can design architecture based on the Purdue model, and knows how to passively audit PLCs. Engaging such an integrator is the only way to ensure that security will support production continuity, not disrupt it.
Why the IT method does not transfer
Three habits that work in IT are unusable on a production network. Active scanning can knock over a controller that has never seen unexpected traffic. Patching may be forbidden outside a vendor-validated release, sometimes for years. Automatic isolation of a suspicious host — the standard response action — can stop a line and create a safety event. Compliance work that reuses the IT playbook therefore fails in the place the regulation cares about most.
An assessment built for the control environment rather than the office one is what NIS2 for OT covers.
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