Introduction
Industrial Control Systems (ICS) represent some of the highest-value, most vulnerable assets in Indian enterprises. A successful cyberattack on an ICS can halt manufacturing, damage expensive equipment, cause environmental incidents, and in critical infrastructure settings, threaten human safety. Yet most Indian industrial organisations are significantly underinvested in ICS security.
This guide provides practical, implementable steps to secure ICS environments — acknowledging the real-world constraints of industrial settings, including legacy systems, operational continuity requirements, and vendor support limitations.
The ICS Security Challenge
- Availability is paramount — downtime can cost lakhs per minute
- Safety takes precedence — controls must not interfere with safety systems
- Legacy systems dominate — often running unsupported OS
- Vendor restrictions apply — unauthorised changes void support
ICS Security Assessment — Start Here
- Asset inventory — Document all ICS components
- Network architecture review — Map IT/OT connections
- Vulnerability assessment — Use passive scanning
- Risk assessment — Identify critical systems
- Gap analysis — Compare against IEC 62443
Priority ICS Security Controls
1. Network Segmentation — Highest Priority
Separate OT from IT networks using the Purdue Model. Use industrial DMZ to manage communication between OT and IT systems.
2. OT Asset Inventory and Visibility
Deploy passive asset discovery tools like Claroty, Dragos, Nozomi, Microsoft Defender for IoT.
3. Secure Remote Access
- MFA for all sessions
- Session recording
- Just-in-time access
- Granular access control
4. OT Network Monitoring
Deploy monitoring tools to detect anomalous industrial behaviour without disrupting operations.
5. Patch Management for OT
- Prioritise internet-facing systems
- Test patches before deployment
- Use maintenance windows
- Apply compensating controls when patching is not possible
6. Backup and Recovery for OT
Back up PLC programs, configurations, and data. Maintain offline backups and test recovery regularly.
7. Physical Security
- Control access to critical facilities
- Block USB ports
- Secure field devices
Building an OT Security Roadmap
| Phase | Timeline | Priority Activities |
|---|---|---|
| Phase 1 — Visibility | Months 1–3 | Asset inventory, network mapping, monitoring |
| Phase 2 — Protection | Months 3–6 | Segmentation, remote access, USB controls |
| Phase 3 — Detection | Months 6–9 | SIEM integration, anomaly detection |
| Phase 4 — Response | Months 9–12 | Incident response, backup testing |
| Phase 5 — Governance | Ongoing | IEC 62443 alignment, training |
How Vedtam Can Help
Vedtam's OT Security Services provide Indian industrial organisations with expertise, tools, and implementation support for ICS security programmes.
Visit vedtam.com/solutions/ot-security/ for more information.
Secure your industrial control systems today.
Free OT security assessment: vedtam.com/contact/ | +91 98915 55588
Published by Vedtam Cybersecurity Team | Vedtam Tech Solutions, Ghaziabad, India
