Why Your PLC Needs Cyber Hardening

 

 

PLC Cyber Security: The Hidden Weak Link in Industrial Automation

From water treatment plants to manufacturing lines, Programmable Logic Controllers (PLCs) are the unseen engines of Australian industry. Yet many still run on technology from the 1990s — long before today’s cyber threats existed.

As these PLCSs are now connected to business and cloud systems, they’ve become exposed to risks their original designers never imagined. Without PLC cyber hardening, a single compromise can lead to production downtime, safety incidents, or even environmental impact.

Why Legacy PLCs Need Cyber Security Protection

Older PLCs were designed for reliability, not resilience against hackers. Built for isolated, air-gapped systems, they now sit at the junction of IT and Operational Technology (OT) — and are a prime target for cyber attackers.

Common PLC Cyber Security Risks

• Network exposure: Once-isolated controllers are now linked to business and cloud systems, creating potential attack paths.
• Visibility gaps: Standard IT security tools can’t interpret industrial protocols like Modbus or DNP3.
• Rising threat activity: Global attacks on industrial control system security environments have surged, with critical infrastructure experiencing record downtime costs.

Protecting these assets isn’t just an IT function — it’s essential to operational continuity.

How PLC Cyber Hardening Strengthens Industrial Network Security

PLC cyber hardening is more than software updates; it’s about implementing layered defences that secure your industrial control systems without disrupting production.

Cromarty’s approach to PLC cyber security includes:

• Risk and vulnerability assessments — a detailed review of your control system network to pinpoint weak links.
• Network segmentation and industrial firewalls — isolating PLCs from corporate traffic to reduce exposure.
• Secure remote access — applying zero trust principles and multi-factor authentication for maintenance and support.
• Penetration testing and architecture design — identify and fix weaknesses before attackers do.
• Compliance and governance support — alignment with the SOCI Act 2018, IEC 62443, and Australian Critical Infrastructure frameworks.
• Incident response and recovery planning — minimising downtime and improving resilience.
• Continuous monitoring — 24/7 network visibility with automated threat detection and response.

These measures form a holistic industrial cyber security strategy that protects both operational technology and business systems.

Cromarty: Australia’s Partner in PLC Cyber Security

With more than 35 years of automation experience, Cromarty has been trusted by leading Australian industries to design, integrate, and secure complex control systems.

Why Choose Cromarty for PLC Cyber Hardening

• End-to-end expertise: From automation design to cyber defence — one team, one solution.
• Certified quality: Supported by an independently verified Quality Management System.
• Security vision: Focused on protecting Australia’s critical infrastructure through secure-by-design engineering.
• Proven results: Supporting clients across water, energy and manufacturing.

Cromarty understands the balance between uptime, safety, and compliance. Our PLC cyber security solutions integrate seamlessly into your operations — enhancing productivity while protecting against modern threats.