OT Security for Industrial and Critical Infrastructure Environments
Operational Technology and Industrial Control Systems demand a different security approach. Spharaka Signal™ delivers passive-first asset visibility, protocol-aware threat detection, and continuous compliance across OT and ICS networks, feeding unified detection and response through Spharaka Sphere™.
The OT Security Problem
Industrial environments run on legacy protocols, fragile controllers, and uptime SLAs that make traditional IT security tools unsafe to deploy. Active scanning can crash PLCs. Missing asset inventory means unknown exposure. IT-centric SIEMs cannot parse Modbus, DNP3, or S7. Attackers targeting critical infrastructure exploit exactly this visibility gap.
- Unknown OT assets, protocols, and firmware versions
- IT security tools too intrusive for production networks
- No shared context between OT anomalies and IT alerts
- Compliance evidence gathered manually for every audit cycle
How Spharaka Addresses OT Security
Spharaka Signal™ analyses OT and ICS traffic passively, discovers every asset, learns baseline behaviour, and detects intrusions without touching production devices. Findings correlate with IT telemetry inside Spharaka Sphere™ for one unified SOC view across IT and OT.
- Passive-first asset discovery across OT, ICS, IoT, and IIoT
- Deep protocol parsing for industrial and control-system protocols
- Behavioural baselining for controllers, workstations, and process traffic
- Continuous compliance monitoring for OT frameworks
- Unified IT + OT detection and response through Spharaka Sphere™
- SAGE™-powered autonomous investigation of OT alerts
Where OT Security Fits Inside Spharaka
Signal™ is the OT-native sensor layer. Every validated OT event is investigated by AuraXP™, correlated with IT identity, endpoint, and cloud signals, and routed through SOAR-governed response with human-in-the-loop approvals for any action that touches a production system.
Securing a network you are not allowed to touch
Every step here is shaped by one constraint: the techniques IT security depends on, scanning, agents, patching and rebooting, are unavailable or unsafe on a production control system.
Observe passively
Sensors read mirrored traffic from a SPAN port, a network tap or ERSPAN. Nothing is injected into a safety controller. This is the default rather than an option because active scanning has caused outages on production control systems, and an outage caused by a security tool ends the security programme.
Build the device-of-record
Most industrial estates have no accurate inventory, and the drawings are years out of date. Devices are identified from the traffic they produce: make, model, firmware version, protocol role and where they sit in the Purdue hierarchy, without ever asking them a question.
Read the protocol properly
Industrial protocols are decoded at register level, so a write that changes a setpoint is legible as that rather than as a TCP session on port 502. This is the difference between seeing traffic and seeing what the traffic does, and it is where IT tooling stops.
Baseline the process
Control traffic is highly repetitive, which is an advantage: normal is genuinely narrow. Baselines cover which controller talks to which, at what interval, with which command types and which value ranges, so a deviation is meaningful rather than merely unusual.
Correlate with IT
Almost every OT intrusion arrives through IT. Findings correlate with enterprise telemetry inside Sphere, so a compromised engineering workstation and an anomalous controller command are one investigation rather than two consoles that never speak.
Evidence continuously
Asset inventory, configuration baselines, patch posture, segmentation conformance, access records and change history map onto specific controls in the standards that apply, so compliance is a continuous record rather than an assembly exercise before an audit.
What it sees, and what it will not do
In OT, the list of things a platform declines to do matters as much as the list of things it can.
Protocol families decoded
- Modbus TCP and RTU
- DNP3 and IEC 60870-5-104
- EtherNet/IP and CIP
- PROFINET and PROFIBUS
- S7comm and S7comm-plus
- OPC UA and OPC DA
- BACnet, for building systems on the same network
What it identifies
- PLCs, RTUs and intelligent electronic devices
- HMIs, historians and engineering workstations
- Safety-instrumented systems, flagged as such
- Firmware versions and known vulnerabilities
- Purdue level and segmentation conformance
- Unmanaged IoT and IIoT sharing the network
Standards evidenced
- IEC 62443, including 62443-3-3 system requirements
- NERC CIP for bulk electric system operators
- NIST SP 800-82r3
- AWWA G430 for water and wastewater
Active OT polling exists but is opt-in and explicitly scoped, never a default. Response actions touching a controller are placed outside the autonomous envelope in AirWatch as a matter of course, not as a customer configuration choice.
Why IT security tooling does not transfer
This is not a claim that IT tools are poor. It is that four assumptions they are built on are false in an industrial network.
| Aspect | IT security tooling | Spharaka |
|---|---|---|
| Priority order | Confidentiality, then integrity, then availability. A host can be isolated while someone investigates. | Availability first. Stopping a process has a physical and sometimes a safety consequence, so containment is bounded differently. |
| Discovery method | Active scanning and authenticated agents, both of which are normal and safe on a corporate network. | Passive observation only by default. Agents cannot be installed on a PLC and scanning it has caused outages. |
| Protocol understanding | Sees a TCP session on port 502. Cannot distinguish a routine poll from a write that changes a burner setpoint. | Register-level decoding, so the command and its value are the unit of analysis rather than the packet. |
| Patching | Assumes a monthly cycle and treats an unpatched host as a finding to remediate. | Assumes unpatchable is the normal case for equipment with a thirty-year life, and shifts to segmentation and compensating controls that can be evidenced. |
| Authentication | Expects identity on the wire, and treats its absence as a misconfiguration. | Most industrial protocols predate authentication entirely, so trust is established from position, pattern and process rather than from credentials. |
| Compliance | Mapped to IT frameworks that say little about zones, conduits or safety integrity levels. | Mapped to IEC 62443, NERC CIP, NIST SP 800-82r3 and AWWA G430, evidenced continuously from data already collected. |
An IT intrusion that reached the plant floor
The usual shape of an OT incident. The attacker never attacked an industrial protocol; they used an engineering workstation that was entitled to.
A process engineer's laptop is compromised through a phishing message. Sphere detects the credential compromise on the enterprise side and begins investigating. Nothing has touched the plant network yet.
The account authenticates to an engineering workstation inside the industrial DMZ. This is permitted: that engineer administers it. A conventional OT tool sees an authorised login and an IT tool loses sight at the boundary.
Signal observes the workstation opening sessions to four PLCs it has not addressed in sixty days, and reading configuration from all four. Read operations, no writes, entirely within what the workstation may do.
Because both halves are one platform, the credential compromise and the unusual controller access are one case. Neither half would have justified escalation alone; together the sequence reads as reconnaissance ahead of a process attack.
AirWatch permits revoking the identity session and isolating the laptop on the enterprise side. Anything touching the four PLCs or the workstation inside the DMZ is outside the envelope, and is staged for the plant manager with the evidence.
The plant manager reviews the case during a shift handover and authorises isolating the workstation at a moment that does not interrupt the process, which is a decision only they can make.
The containment that mattered happened autonomously on the IT side within seconds. The containment that could have stopped production waited eleven minutes for the person accountable for production, which is the correct division and the reason the platform is trusted on that network at all.
What to test in an OT security evaluation
OT evaluations carry a risk that IT evaluations do not: the trial itself can cause the outage. These four questions come first.
What does it transmit onto my network?
Ask for the exact answer, and verify it with a tap during the trial. A platform that is passive by default but polls opportunistically is a different risk from one that never transmits, and the difference is not always in the datasheet.
Run it on production traffic
Passive collection means an evaluation can run against the real network without a change window, which is the whole advantage. A vendor who needs a maintenance window to start a trial has told you their collection is not passive.
How much of my estate did it identify?
Compare the discovered inventory against whatever record you have, then investigate the difference. The devices neither list knows about are the finding, and they are usually the reason the project was funded.
Which actions can it take on a controller?
The correct answer is none without explicit approval. A platform willing to act autonomously on a safety-instrumented system is offering a new class of incident, and the policy model matters more here than anywhere else on the estate.
Frequently asked questions
What is OT security?
OT security protects Operational Technology and Industrial Control Systems, the hardware and software that monitor and control physical processes in manufacturing, energy, utilities, transport, and critical infrastructure.
How is OT security different from IT security?
OT environments prioritise safety and uptime over confidentiality, run legacy protocols like Modbus and DNP3, and cannot tolerate active scanning. OT security must be passive-first, protocol-aware, and integrated with plant operations.
How does Spharaka provide OT security?
Spharaka Signal™ delivers passive OT visibility, protocol-aware threat detection, and continuous compliance. It feeds Spharaka Sphere™ so IT and OT signals are investigated and responded to through one autonomous SOC.
Does Spharaka support air-gapped OT deployments?
Yes. Signal and the Sphere platform support fully on-premises and air-gapped deployment, with local SAGE™ AI inference and no dependency on external internet connectivity.
Explore related capabilities
Spharaka Signal™
The OT and ICS security product powering this capability.
Spharaka Sphere™
Unified autonomous cyber defence for IT and OT.
AI SOC Platform
Where OT and IT signals converge for unified operations.
Autonomous Threat Hunting
Continuous hunting across IT and OT telemetry.
Manufacturing Solutions
Industry blueprint for IT + OT cybersecurity.
SAGE™ AI Model
Spharaka's proprietary Cybersecurity SLM that powers this capability.
Related use cases and guides
A process line with a mirror tap feeding a sensor set apart from it, traffic travelling one way only, and the active scan path barred.
Unified IT and OT defence for industrial operations.
Government
Critical infrastructure and national systems.
Evaluating Autonomous Defence
Evaluation tests for industrial environments.
See Spharaka Signal in action
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