Industrial control systems manage physical processes across critical infrastructure. Power generation, water treatment, manufacturing, and transportation all rely on ICS. These systems were designed for reliability, not security.
Air gaps provide limited protection. Many supposedly air-gapped systems connect to corporate networks for remote monitoring or updates. Engineers use USB drives, carrying malware between networks. True isolation is rare and difficult to maintain.
Legacy systems plague industrial environments. ICS components operate for decades without updates. Ancient operating systems, unsupported software, and hardware predating modern security concepts remain in production. Patching often isn’t possible without extensive testing and scheduled outages.
Network segmentation isolates critical systems. OT networks should be completely separate from IT networks. When integration is necessary, heavily protected DMZs with unidirectional gateways prevent attacks from IT systems reaching industrial controllers. Comprehensive external network penetration testing examines whether network segmentation actually prevents external access to industrial control systems.
Remote access creates massive risks. Vendors need remote access for support. These connections often lack proper security controls. Attackers compromise vendor systems, then pivot through remote access connections to customer ICS networks.
William Fieldhouse, Director of Aardwolf Security Ltd, observes: “ICS security requires balancing safety, availability, and security. System changes require extensive testing because failures can cause physical harm or environmental damage. This makes rapid security updates nearly impossible. Defence in depth becomes critical.”
Protocol security in industrial networks differs from IT environments. ICS protocols like Modbus, DNP3, and others lack authentication and encryption. Attackers on ICS networks can send commands to controllers without authentication. Protocol gateways and encryption overlays add security to insecure protocols.
Physical security prevents direct controller access. Industrial environments have controllers in accessible locations. Attackers with physical access can connect directly, reconfigure systems, or install malicious hardware. Physical access controls protect critical components.
Monitoring industrial networks detects anomalous behaviour. ICS networks have predictable traffic patterns. Unusual commands, unexpected communication patterns, or unauthorised connections all warrant investigation. Specialised ICS monitoring tools understand industrial protocols.
Incident response for ICS requires different procedures. Safety comes first. Disconnecting compromised systems might cause physical damage or endanger personnel. Response plans must account for these unique considerations.
Security assessments of ICS environments need specialised expertise. Standard penetration testing techniques can damage industrial equipment. Assessors need understanding of both security and industrial systems. When you request a penetration test quote for ICS security, verify the team has appropriate ICS experience and certifications.
Vendor management matters enormously. ICS vendors provide equipment, software, and support. Their security practices directly impact customer security. Vendor assessments, security requirements in contracts, and monitoring of vendor access all reduce risk.
