OT/ICS Security Platform Comparison 2026: Dragos vs Claroty vs Nozomi Networks vs Microsoft Defender for IoT

The Purdue Model (also called the Purdue Reference Model or ISA/IEC 62443 reference architecture) defines five levels of an industrial control system environment: Level 0 (field devices -- sensors, actuators), Level 1 (basic control -- PLCs, RTUs), Level 2 (supervisory control -- HMI, SCADA), Level 3 (manufacturing operations -- historians, ERP integration), and Levels 4-5 (enterprise IT -- corporate network, internet). The security boundary between Level 3 (OT) and Level 4 (IT) is the most critical segmentation point in any OT environment.

IT security tools fail at Levels 0-2 for three reasons. First, OT devices run proprietary operating systems (often Windows XP, Windows CE, or embedded RTOS) that cannot run endpoint agents and may crash or malfunction when receiving unexpected network traffic. Active scanning -- which IT vulnerability scanners perform by default -- can cause PLCs and RTUs to reboot, drop connections, or enter fault states. Second, OT protocols (Modbus, DNP3, Profinet, EtherNet/IP, IEC 61850) are not HTTP or TCP applications. A generic network security tool cannot distinguish a legitimate setpoint change from a malicious command injection using Modbus function code 6. Third, OT patch cycles are measured in years, not weeks -- a vulnerability in a PLC firmware may not be patchable without a production shutdown and vendor certification, requiring compensating controls rather than remediation.

OT security platforms address these constraints through passive monitoring: they read traffic from network TAPs or SPAN ports, never injecting packets or establishing connections to OT devices, and build asset inventories and detect threats purely from observed traffic patterns.

OT-targeting threats have escalated from opportunistic ransomware operators reaching OT networks via IT-OT convergence to sophisticated nation-state actors with purpose-built ICS malware. Dragos tracks 13 threat groups with demonstrated capabilities to disrupt, degrade, or destroy industrial operations -- including CHERNOVITE (PIPEDREAM malware, capable of attacking safety instrumented systems), KOSTOVITE (targeting electric utilities), and KAMACITE (persistent access to energy sector networks for potential future disruption).

The ransomware intersection with OT continues to expand. Most ransomware operators do not target OT directly -- they encrypt IT systems that OT environments depend on for historian access, engineering workstation operation, and ERP integration. The Colonial Pipeline attack (2021) remains the canonical example: ransomware on the IT network caused OT shutdown as a precaution, creating fuel supply disruption without the ransomware ever reaching Level 1 or 2 systems.

Purpose-built ICS malware (TRITON/TRISIS, Industroyer/Crashoverride, INCONTROLLER/PIPEDREAM) represents the highest-severity threat category: software designed to manipulate specific OT protocols and device types to cause physical effects. PIPEDREAM, disclosed in 2022 and attributed to CHERNOVITE, is the most capable OT attack framework ever publicly documented, capable of disrupting safety instrumented systems across multiple industrial sectors.

Dragos is the most OT-specialized platform in this comparison, built exclusively for industrial cybersecurity by founders who came from the NSA and ICS CERT threat analysis community. The platform's defining differentiator is intelligence depth: Dragos tracks more named OT threat groups, with more detailed behavior analysis, than any other vendor. The WorldView threat intelligence feed -- included in the Dragos Platform subscription -- provides ICS-specific threat intelligence that has no equivalent in IT security threat feeds.

The Dragos Platform deploys as a software appliance (physical or virtual) and performs passive network monitoring via SPAN port or TAP. Asset identification uses protocol parsing for 1,000-plus industrial protocols and fingerprints devices by their communication patterns, vendor-specific attributes, and firmware version indicators visible in traffic. The platform builds a detailed asset inventory (make, model, firmware version, communication patterns, protocol usage) without ever querying OT devices directly.

Threat detection in Dragos relies on behavioral analytics and threat intelligence correlation. The platform's analytics are built around known adversary behavior patterns from the threat groups Dragos tracks -- detection rules written for CHERNOVITE's PIPEDREAM techniques, KAMACITE's lateral movement patterns, and VOLT TYPHOON's living-off-the-land behaviors in OT environments.

The Dragos OT Watch managed service is the platform's operational complement: Dragos analysts who have specific ICS expertise monitor customer environments, validate alerts, and provide incident response support. For industrial organizations without in-house OT security expertise -- which is most of them -- OT Watch is a significant operational advantage.

Pricing: Dragos licenses per asset monitored. Enterprise deployments at 500 to 2,000 monitored devices typically land between $300,000 and $1.5 million per year including threat intelligence.

Claroty has expanded from a pure OT monitoring vendor into an Extended IoT (XIoT) security platform that covers OT, IoT, BIoT (building and facility systems), and medical devices under a single platform. This expansion reflects the reality of converged enterprise environments where the same network now carries industrial traffic, smart building systems (HVAC, access control, power management), and medical devices alongside traditional OT.

The Claroty Platform deploys as an on-premises appliance, as a cloud-connected appliance, or as a SaaS-native deployment (Claroty SaaS), the most recent architectural option that eliminates on-premises infrastructure. Asset discovery covers OT, IoT, and medical devices using passive monitoring augmented by a Safe Active Querying capability that sends minimal, protocol-compliant queries to devices that can tolerate them -- collecting more detailed asset information than pure passive monitoring for devices that support it.

Claroty's vulnerability management integration is stronger than Dragos: the platform correlates asset inventory with CVE data and vendor security advisories, prioritizes vulnerabilities by asset criticality and network exposure, and integrates with IT vulnerability management platforms (Tenable, Qualys) to provide a unified view of OT and IT vulnerability risk. This integration is valuable for organizations that want to extend their existing VM workflow to OT assets.

The Claroty-Rockwell Automation partnership and Claroty-Schneider Electric partnership bring OEM integration with two of the largest industrial equipment vendors, enabling richer asset information for Rockwell and Schneider devices than Claroty can obtain from passive traffic monitoring alone.

Pricing: Claroty licenses per asset. Typically comparable to Dragos pricing for equivalent device counts.

Nozomi Networks is the most deployment-flexible platform of the four, offering the broadest range of deployment form factors: hardware sensors (Nozomi Guardian), software sensors, virtual appliances, and a cloud-native SaaS deployment. Nozomi also has the most extensive OT and IoT device coverage by asset type count and the strongest scalability for large, geographically distributed industrial environments.

The Vantage platform -- Nozomi's cloud-based management layer -- aggregates data from all deployed sensors into a centralized analysis and management console, which is the most operationally practical architecture for organizations with OT environments across multiple facilities or geographies. Remote site sensors send telemetry to Vantage without requiring per-site security operations staff.

Nozomi's AI and machine learning capabilities are the most mature of the four platforms for anomaly detection: the platform builds behavioral baselines for OT traffic patterns, device communication relationships, and process variable behavior, and surfaces deviations that represent both security threats and operational anomalies. This dual use for security and operational monitoring is a significant selling point for OT engineering teams who want visibility into process health alongside security detection.

Nozomi has strong integrations with SIEM platforms (Splunk, Sentinel, IBM QRadar), SOAR platforms, and IT security ecosystems, making it the most IT-security-team-friendly OT monitoring platform. Organizations with mature IT SOC operations that are extending monitoring to OT environments find Nozomi's integration surface easier to work with than Dragos's more OT-specialized interface.

Microsoft Defender for IoT is the OT and IoT monitoring option for organizations that want cloud-native integration with Microsoft Sentinel, a pay-as-you-go pricing model, and the Microsoft support and compliance infrastructure. The platform was significantly enhanced following Microsoft's acquisition of CyberX (2020), which provided the OT-specific protocol analysis and asset discovery capabilities.

Defender for IoT deploys passive network sensors (physical or virtual) that mirror traffic from OT network segments. The platform integrates natively with Microsoft Sentinel: detected OT threats surface as Sentinel incidents, OT asset inventory appears in the Sentinel workspace, and OT alerts correlate with IT security events from Defender for Endpoint and Entra ID in the same investigation timeline. For organizations running Sentinel as their enterprise SIEM, this native integration eliminates a significant custom integration effort.

The platform covers approximately 300 industrial protocols and provides asset inventory for OT, IoT, and medical devices. The Microsoft Threat Intelligence integration provides enrichment for known malicious indicators, though the OT-specific threat intelligence depth trails Dragos WorldView for ICS-specialized threat actor tracking.

Pricing: Defender for IoT uses a committed device model (pay per device per year) with a free tier covering the first 1,000 devices. For Microsoft Sentinel customers, the integration value is immediate and at lower total cost than standalone OT monitoring vendors for equivalent device counts.

The OT security platform decision is determined by your threat model, operational environment, and whether you have in-house OT security expertise or need managed services support.