IT/OT Security Assessment & Convergence Review
Safety-first security assessment of your IT/OT convergence — reviewing network segmentation, industrial protocol security, PLC/HMI/SCADA exposure, and cyber-physical risk aligned to IEC 62443 and NIST SP 800-82.
Convergence · Network · Cyber-Physical Risk
Three assessment dimensions covering every layer of IT/OT security — from boundary architecture through industrial protocol depth to physical consequence risk mapping.
IT/OT Convergence Assessment
Assessing the security of the interface between your enterprise IT network and operational technology environment — reviewing DMZ effectiveness, data diode implementations, unidirectional gateways, and jump server architecture controlling data flow between IT and OT zones per the Purdue Model or ISA/IEC 62443 zone/conduit model.
- Purdue Model architecture review — zone and conduit compliance
- IT/OT DMZ effectiveness and firewall rule review
- Jump server and bastion host configuration assessment
- Unidirectional gateway and data diode verification
- Remote access control review (vendor VPN, remote monitoring)
- Asset inventory — shadow OT device discovery
OT Network Security & Protocol Analysis
Passive analysis (no active scanning that could disrupt OT processes) of industrial network traffic to identify insecure protocol usage, unauthorised communications, and legacy device exposure — covering Modbus, DNP3, IEC 61850, Profinet, EtherNet/IP, and OPC-UA security configuration.
- Passive OT network traffic capture and analysis
- Insecure industrial protocol identification (Modbus TCP, DNP3)
- Unauthorised IT-to-OT communication path discovery
- OT device fingerprinting and exposure mapping
- OPC-UA security configuration review
- Anomalous communication baseline comparison
Cyber-Physical Risk & Compliance
Mapping identified cyber vulnerabilities to potential physical consequences — process disruption, safety system compromise, production loss — and providing a risk-prioritised remediation roadmap aligned to IEC 62443 Security Level targets, NIST SP 800-82, and NIS2 Directive requirements.
- Cyber-to-physical consequence mapping per identified vulnerability
- Safety Instrumented System (SIS) assessment
- IEC 62443 Security Level gap analysis (SL 1-4 target definition)
- NIST SP 800-82 compliance gap identification
- NIS2 Directive essential service operator assessment
- Vendor supply chain cyber risk review
OT Networks Were Designed for Availability, Not for Security
OT environments were engineered decades before cybersecurity was a consideration. PLCs run vendor firmware untouched for 10+ years. HMIs run Windows XP or Windows 7. Industrial protocols like Modbus and DNP3 have no authentication. This architecture, rational in an air-gapped world, becomes critically dangerous when connected — even indirectly — to enterprise IT.
The convergence of IT and OT — through remote monitoring, cloud historian connections, enterprise ERP integration, and remote vendor access — means the air gap most OT operators assumed no longer exists. Nation-state threat actors and ransomware groups actively target OT environments precisely because the security maturity lag creates high-impact, low-difficulty attack opportunities.
Passive-Only Testing
Zero active scanning in production OT — read-only traffic capture and offline configuration review
Safety Planning First
Written safety plan approved by your engineering team before any assessment activity begins
Consequence-Mapped Risk
Vulnerabilities rated by physical consequence, not CVSS — the risk language OT leadership understands
Regulatory Alignment
IEC 62443 Security Level gap analysis and NIS2 essential service operator compliance assessment
5-Phase IT/OT Assessment Methodology
From safety planning through passive discovery, architecture review, compliance assessment, and consequence-mapped remediation roadmap respecting OT operational constraints.
Scoping & Safety Planning
Before any assessment activity begins, a detailed scoping session with your OT/engineering team defines safe assessment boundaries — documenting which systems are in scope, which must remain untouched, what passive vs. active testing is permitted, and the change control process for any activities requiring engineering approval.
Passive Network Discovery & Traffic Analysis
Deploying passive network taps or SPAN port capture — never active scanning tools that could disrupt PLC/RTU communications — to capture OT network traffic for protocol analysis, device fingerprinting, unauthorised communication path identification, and anomalous session detection. Activity is read-only with zero risk to operational processes.
Architecture & Configuration Review
Off-network review of OT architecture documentation, firewall rules, switch configurations, remote access logs, and device configuration backups — identifying segmentation weaknesses, insecure remote access paths, overly permissive IT/OT boundary rules, and vendor access sessions without adequate monitoring or time-limiting controls.
Vulnerability & Compliance Assessment
Correlated assessment of identified vulnerabilities against IEC 62443, NIST SP 800-82, and NIS2 requirements — mapping each finding to a physical consequence scenario, assigning risk severity based on process impact rather than CVSS score alone, and identifying compliance gaps requiring remediation.
Report, Consequence Mapping & Roadmap
Comprehensive assessment report including asset inventory with risk classification, architecture findings with consequence-mapped risk scores, IEC 62443 Security Level gap analysis, compliance findings, and a prioritised remediation roadmap respecting OT operational constraints — distinguishing immediate mitigations from architectural changes requiring planned maintenance windows.
Comprehensive OT Security Coverage
From IT/OT segmentation through industrial protocols, remote access, legacy device exposure, safety system independence, and regulatory compliance.
IT/OT Network Segmentation
Review of your IT/OT boundary architecture — Purdue Model compliance, DMZ effectiveness, firewall rule permissiveness, and unidirectional gateway implementation verifying IT-to-OT traffic is controlled and monitored at every crossing point.
Industrial Protocol Security
Passive analysis of Modbus, DNP3, IEC 61850, Profinet, EtherNet/IP, and OPC-UA traffic — identifying plaintext communications, unauthenticated commands, and protocol-level vulnerabilities that allow adversaries to send unauthorised commands to PLCs and RTUs.
Remote Access & Vendor Management
Review of all remote access paths to your OT environment — vendor VPN sessions, remote monitoring connections, and cloud historian links — validating authentication strength, session recording, time-limiting controls, and privileged access management.
Legacy Device Exposure
Asset inventory and risk classification of end-of-life OT devices — PLCs, RTUs, HMIs, and historians running unsupported operating systems or firmware — with compensating control recommendations for systems that cannot be patched or upgraded.
Safety System Independence
Assessment of your Safety Instrumented System (SIS) independence from the Basic Process Control System (BPCS) and enterprise network — verifying that a cyber compromise of IT or BPCS layers cannot propagate to safety instrumented functions.
IEC 62443 & NIS2 Compliance
Gap analysis against IEC 62443 Security Level targets and NIS2 Directive requirements for operators of essential services — identifying which zones/conduits fail to meet their Security Level target and which NIS2 obligations require specific technical or procedural controls.
OT Security That Respects the Operational Environment
We understand that in OT, availability is not just a preference — it is a contractual, safety, and operational requirement. Our assessment respects that constraint at every stage.
Safety-First Methodology
We never use IT-style active scanners in OT environments. Every technique is pre-approved with your process and safety engineers. Passive-only in live production. Zero disruption. Zero risk to operational availability.
Physical Consequence Mapping
We do not rate OT vulnerabilities by CVSS. We map each finding to a physical consequence scenario — process disruption, production shutdown, safety system compromise — giving leadership the risk language OT decisions require.
OT-Specialist Assessors
Our OT assessors have direct industrial experience — understanding engineering constraints, change control processes, and the vendor ecosystem that makes OT security fundamentally different from IT security assessment.
Regulatory Alignment
IEC 62443 Security Level assessments, NIST SP 800-82 gap analysis, and NIS2 Directive essential service compliance — delivered by assessors who understand OT regulatory requirements, not just IT security frameworks.
OT Security Platforms & Tools We Use
Frequently Asked Questions
Everything you need to know about IT/OT security assessment
Secure Your OT Environment Before a Threat Actor Does
Nation-state actors and ransomware groups are actively targeting OT environments. Schedule a safety-first scoping call to define your IT/OT assessment scope and build your IEC 62443-aligned improvement roadmap.
Get in Touch
Ready to secure your future? Reach out to us for a consultation.