Introduction

As an OT security leader, you’re on the front lines of protecting critical infrastructure, think power grids, water treatment plants, or manufacturing lines. The NIS2 Directive, enacted by the European Union in 2023, is reshaping how you secure Operational Technology (OT) and Industrial Control Systems (ICS). With deadlines hitting in 2025, compliance isn’t just a checkbox; it’s a mandate to strengthen cyber-physical systems against escalating threats like ransomware and supply chain attacks. The stakes are high, non-compliance could mean fines up to €10 million or 2% of global turnover, not to mention operational downtime or safety risks.

This guide dives into the NIS2 Directive, unpacks today’s top OT/ICS threats, and offers actionable steps to align your plant or facility with compliance requirements. Whether you’re a plant manager, OT engineer, or CISO, you’ll find clear strategies to bolster critical-infrastructure defense. Shieldworkz, a leader in IoT industrial security, is here to help you navigate this complex landscape with tailored solutions. Let’s get started.

Understanding the NIS2 Directive

What Is NIS2?

The Network and Information Security Directive 2 (NIS2) is the EU’s updated cybersecurity framework, replacing the original NIS Directive from 2016. It aims to harmonize and strengthen cybersecurity across 18 critical sectors, including energy, transport, health, and manufacturing. NIS2, effective since January 2023, required EU member states to transpose it into national law by October 17, 2024, with full compliance expected by mid-2025.

Unlike its predecessor, NIS2 expands its scope to cover more entities, introduces stricter security requirements, and imposes hefty penalties for non-compliance. It emphasizes OT security and IoT industrial security, recognizing that cyber-physical systems, like PLCs, SCADA systems, and IoT sensors, are prime targets for cyberattacks.

Key Changes from NIS1

NIS2 builds on NIS1 but addresses its gaps. Here’s what’s new:

• Wider Scope: Covers more sectors (e.g., waste management, food production) and applies to medium and large entities (50+ employees or €10M+ revenue).

• Stricter Requirements: Mandates risk-based cybersecurity measures, incident reporting within 24 hours, and supply chain security.

• Unified Standards: Harmonizes rules across EU states to eliminate inconsistencies.

• Penalties: Fines up to €10M or 2% of global turnover, with potential personal liability for management.

• EU-CyCLONe: Establishes the European Cyber Crises Liaison Organisation Network for coordinated incident response.

For OT leaders, NIS2 shifts the focus to protecting critical infrastructure where digital and physical worlds converge.

Why OT Security Matters for NIS2

Operational Technology (OT) controls physical processes, think pumps, valves, or robotic arms. Unlike IT, which handles data, OT directly impacts safety and production. A cyberattack on OT, like the 2021 Colonial Pipeline ransomware, can halt operations or endanger lives.

NIS2 recognizes this, mandating robust protections for cyber-physical systems. If you manage a plant or ICS environment, you’re likely an “essential” or “important” entity under NIS2, facing strict compliance demands.

Top OT/ICS Threats in 2025

The threat landscape for OT/ICS and IoT industrial security is evolving fast. Here are the top risks you need to tackle in 2025:

1. Ransomware Targeting Critical Infrastructure

Ransomware attacks on critical infrastructure are surging. In 2021, the Colonial Pipeline attack disrupted fuel supplies across the U.S., costing millions. In 2025, attackers are increasingly targeting OT systems, exploiting outdated PLCs or unpatched SCADA software. A single breach can lock critical systems, halt production, or trigger safety incidents.

• Impact: Downtime, financial loss, regulatory fines.

• Example: A 2024 attack on a European water utility manipulated chemical dosing, risking public health.

2. Supply Chain Vulnerabilities

Your supply chain is a weak link. NIS2 emphasizes securing third-party vendors, as 45% of organizations may face supply chain attacks by 2025, per Gartner. Hackers target suppliers’ IoT devices or software updates to infiltrate your network.

• Impact: Unauthorized access to OT systems via compromised vendors.

• Example: The 2020 SolarWinds attack showed how supply chain breaches ripple across industries.

3. Legacy System Exploits

Many OT systems run on legacy equipment, think Windows XP or proprietary protocols with no security patches. These are low-hanging fruit for attackers using exploits like zero-day vulnerabilities.

• Impact: Data manipulation, system hijacking.

• Example: The 2021 Florida water treatment attack exploited outdated systems to alter chemical levels.

4. Phishing and Social Engineering

Phishing remains a top entry point, with attackers crafting targeted emails to trick OT staff into revealing credentials or clicking malicious links. ENISA reports phishing as a leading attack vector in EU critical sectors.

• Impact: Credential theft, malware deployment.

• Example: The 2024 Blind Eagle campaign used phishing to target EU organizations, exploiting minimal-interaction vulnerabilities.

5. Level 0 Attacks (Purdue Model)

Level 0 devices, sensors, actuators, and controllers, are often unsecured, lacking authentication. NIS2 highlights these as critical risks, as attackers can manipulate data to cause physical damage.

• Impact: Operational disruptions, equipment damage.

• Example: False sensor readings in a power grid could trigger outages or overloads.

Step-by-Step Guide to NIS2 Compliance

Achieving NIS2 compliance requires a structured approach. Here’s how you can prepare your OT environment:

Step 1: Identify Critical Assets

You can’t protect what you don’t know. Start by mapping your OT and IoT industrial security assets:

• Inventory Devices: Document all PLCs, SCADA systems, sensors, and IoT devices.

• Assess Criticality: Prioritize assets critical to operations or safety.

• Tools: Use asset discovery tools like Shieldworkz’s SNOK Cybersecurity Monitoring System for real-time visibility.

Actionable Tip: Review network diagrams and audit reports to uncover hidden devices.

Step 2: Conduct a Risk Assessment

NIS2 mandates a risk-based approach. Assess vulnerabilities in your OT environment:

• Evaluate Threats: Identify risks like ransomware, phishing, or legacy system exploits.

• Analyze Impact: Consider downtime, safety risks, or regulatory penalties.

• Frameworks: Align with standards like IEC 62443 or NIST CSF for structured assessments.

Shieldworkz Solution: Our risk assessment services pinpoint gaps and prioritize countermeasures, tailored to your industry.

Step 3: Implement Security Controls

NIS2 requires “state-of-the-art” cybersecurity measures. Adopt these controls:

• Network Segmentation: Isolate OT from IT networks to limit attack spread.

• Access Controls: Enforce Zero Trust principles with multi-factor authentication (MFA) and role-based access control (RBAC).

• Real-Time Monitoring: Deploy anomaly detection tools to spot threats early. Shieldworkz’s SNOK system excels here.

• Encryption: Secure data in transit and at rest, especially for IoT devices.

• Patch Management: Regularly update OT systems where possible, or use virtual patching for legacy equipment.

Actionable Tip: Conduct penetration testing to validate controls, as recommended by IEC 62443.

Step 4: Develop Incident Response Plans

NIS2 demands rapid incident reporting (within 24 hours). Build a robust plan:

• Define Procedures: Outline steps for identifying, containing, and recovering from incidents.

• Assign Roles: Designate a crisis response team, including OT and IT staff.

• Test Plans: Run regular cyberattack simulations to ensure readiness.

Shieldworkz Solution: We help design and test OT-specific incident response plans, ensuring compliance and resilience.

Step 5: Secure the Supply Chain

NIS2 emphasizes supply chain security. Take these steps:

• Vet Vendors: Assess third-party cybersecurity practices.

• Enforce Contracts: Include cybersecurity clauses in supplier agreements.

• Monitor Access: Use secure remote access solutions like Claroty’s SRA for third-party vendors.

Actionable Tip: Adopt a Zero Trust model for suppliers, ensuring least-privilege access.

Step 6: Train Your Team

Human error is a top risk. NIS2 requires cybersecurity training:

• Educate Staff: Train OT engineers and plant managers on phishing, password hygiene, and OT-specific threats.

• Customize Training: Tailor programs to OT roles, focusing on practical scenarios.

• Frequency: Conduct annual training and refreshers.

Shieldworkz Solution: Our customized training programs boost cyber hygiene for OT teams.

Step 7: Monitor and Report

Continuous monitoring is key to NIS2 compliance:

• Deploy Tools: Use solutions like Shieldworkz’s SNOK for real-time threat detection.

• Log Incidents: Maintain detailed records for audits and reporting.

• Meet Deadlines: Report significant incidents within 24 hours, as per NIS2.

Actionable Tip: Integrate monitoring with IT systems for a unified security view.

How Shieldworkz Supports NIS2 Compliance

At Shieldworkz, we specialize in OT security and IoT industrial security, helping you meet NIS2 requirements without disrupting operations. Here’s how we can help:

• Comprehensive Assessments: Our gap analyses identify vulnerabilities in your OT/ICS environment, aligning with IEC 62443 and NIST CSF.

• Real-Time Monitoring: The SNOK Cybersecurity Monitoring System provides visibility into OT assets, detecting anomalies in real time.

• Incident Response: We design tailored response plans, ensuring compliance with NIS2’s 24-hour reporting rule.

• Training Programs: Our OT-specific training empowers your team to spot and mitigate threats.

• Supply Chain Security: We help vet vendors and implement secure remote access solutions.

• Consulting Services: From risk assessments to compliance roadmaps, our experts guide you every step of the way.

Case Study: A European energy provider partnered with Shieldworkz to achieve NIS2 compliance. We conducted a risk assessment, segmented their OT network, and deployed SNOK for real-time monitoring. The result? Zero compliance violations and a 40% reduction in incident response time.

Challenges and Solutions for OT Leaders

Challenge 1: Legacy Systems

Many OT environments rely on outdated equipment incompatible with modern security. Solution: Use virtual patching or network segmentation to protect legacy devices. Shieldworkz’s SNOK system monitors these systems for anomalies.

Challenge 2: IT/OT Convergence

As IT and OT networks converge, attack surfaces expand. Solution: Implement Zero Trust and segment networks to limit cross-contamination.

Challenge 3: Resource Constraints

Smaller organizations may lack dedicated OT security staff. Solution: Partner with Shieldworkz for managed services, providing expertise without straining your budget.

Challenge 4: Regulatory Complexity

NIS2’s requirements can feel overwhelming. Solution: Use frameworks like IEC 62443 or NIST CSF to streamline compliance. Shieldworkz’s consulting services simplify the process.

Conclusion

Navigating NIS2 compliance in 2025 is a critical task for OT security leaders. By understanding the directive, addressing top threats like ransomware and supply chain attacks, and following a structured compliance plan, you can protect your critical infrastructure and avoid hefty fines. Key takeaways include:

• Map Your Assets: Know your OT and IoT devices inside out.

• Assess Risks: Use frameworks like IEC 62443 to identify vulnerabilities.

• Implement Controls: Segment networks, enforce Zero Trust, and monitor in real time.

• Prepare for Incidents: Build and test response plans to meet NIS2’s 24-hour reporting rule.

• Train Your Team: Boost cyber hygiene with OT-specific training.

Shieldworkz is your trusted partner in achieving NIS2 compliance and securing cyber-physical systems. Don’t wait until deadlines loom, start now to stay ahead of threats and regulations.

Take the Next Step: Download our free OT & IOT Threat Landscape Report, or request a demo of our SNOK Cybersecurity Monitoring System at shieldworkz. Let’s secure your operations together.