Engineering · Our Own Platform

OT network monitoring that listens — and detects anomalies.

Out of its engineering practice, Aganum has developed its own platform for OT network monitoring with anomaly detection. It works purely passively: it inventories the communicating devices, maps the network topology along the Purdue Model, understands the industrial protocols — and reports anomalies in plain language, with a report at the push of a button. Fully on-premise, without cloud.

Purely passive On-premise Anomaly detection No forced cloud

Built from field experience, not on a drawing board.

The same fundamental problem shows up in project after project: before measures or architecture can even be discussed, the foundation is missing — a complete, dependable picture of what actually exists in the OT network and what communicates with what. Classic IT tools do not fit here, because they can cause damage in a production plant. So Aganum built its own tool that closes exactly this gap.

The problem

Active scans are off-limits in OT — any intervention in the network can disturb a controller or trigger a plant standstill. At the same time, every sound security decision needs a complete asset inventory and an honest picture of the communication relationships. Many companies face exactly this contradiction: they are expected to create visibility, but must not touch the plant to do it.

The idea

A platform that does nothing but listen. It analyzes what the network reveals anyway — traffic and log messages — and builds a complete situation picture from it: devices, communication relationships, vulnerabilities, anomalies. It sends nothing into the OT network itself and is technically incapable of disturbing production.

Six characteristics that make the difference.

Purely passive

The platform only listens and never sends packets into the OT network. It is technically incapable of disturbing, blocking or triggering production — the most important principle in any plant.

On-premise

No cloud backend, no phone-home. All data stays at the plant. Internet is optional, only to update vulnerability and threat lists — and even that can be done offline.

Anomaly detection

Baseline, rules and process analytics check every event: what is normal, what is prohibited, what falls outside the pattern? Anything unusual is reported — put into context rather than dumped as a flood of raw data.

Report at the push of a button

The presentable situation picture as a PDF: management summary, incidents, critical alerts, MITRE overview and zone status — instead of days of manual work in Excel.

OT-native

Understands the industrial language of the machines (Modbus, S7, EtherNet/IP, DNP3 …), detects process anomalies and assigns every device to the Purdue Model — not just the IT traffic around it.

Complements the SIEM

Not a competitor to existing security systems, but their OT supplier: the platform forwards its findings to the central SIEM via Syslog, CEF, LEEF or webhook.

From raw data stream to an assessable incident.

Every single observation passes through the same chain. That is the core: step by step, a raw event becomes an understandable incident in context — enriched with asset role, open vulnerabilities and threat context.

01

Capture

Different log formats are translated into one uniform event (normalization).

02

Evaluate

Baseline (what is normal?), rules (what is prohibited?) and process anomalies check every event.

03

Report

Anything unusual becomes an alert — with asset role, vulnerabilities, threat matches and priority.

04

Correlate

Related alerts are bundled into one incident and mapped to MITRE ATT&CK for ICS.

This is what it looks like in action.

Three excerpts from the interface — captured in a simulated plant environment in which the platform detects an ongoing attack.

Network topology in the Purdue view: an engineering workstation opens conspicuous connections to ten controllers, marked in red
FIG. 01 Purdue topology: an engineering workstation suddenly contacts every PLC in the segment — the platform marks each of these connections as an anomaly. · simulated plant environment · product UI shown in German
Four protocol cards (S7comm, Modbus/TCP, EtherNet/IP, DNP3) with event counts, read/write ratio and detected anomalies
FIG. 02 OT protocols fully decoded: read versus write access per protocol, ports, last activity — and the anomalies that fall outside the pattern. · simulated plant environment · product UI shown in German
MITRE ATT&CK technique panel T0812 Default Credentials with statistics, countermeasures, threat groups and triggered alerts
FIG. 03 MITRE ATT&CK for ICS: every match is mapped to its technique — including countermeasures, known threat groups and the alerts it triggered. · simulated plant environment · product UI shown in German

ALL SCREENSHOTS FROM A SIMULATION ENVIRONMENT — NO CUSTOMER DATA. PRODUCT UI SHOWN IN GERMAN.

Every view is its own tool.

The platform bundles several specialized modules — each one a distinct perspective on the same passively captured data.

01 Asset inventory

The automatic directory of all devices on the network. Devices are recognized and recorded from every event, maintainable with zone, criticality and owner.

02 Network topology

An interactive map: who talks to whom? Switchable to the Purdue Model view. Unwanted zone crossings are instantly highlighted in red.

03 OT protocols

The view of the industrial language of the machines. Recognizes protocols and function codes — say, a read versus a write command to a controller, or program transfers on the network.

04 Process anomalies

OT-specific irregularities right at the production process: a sudden standstill, slow drift, activity outside the shift or a reading outside the permitted range.

05 Vulnerabilities

Recognized products are matched against the official CVE database and the actively-exploited list (CISA KEV) — prioritized by actual exposure.

06 Report

The finished situation picture as a PDF at the push of a button — with management summary, incidents, MITRE overview and zone status.

FlowSR — where deterministic methods hit the wall.

Rules, signatures, baselines — deterministic methods are the foundation of all detection, and they are good. But in real plants they are not enough: the traffic is incomplete, the sensor coverage patchy, and the decisive question remains open — what actually is this device, and what is this connection doing?

So the platform gained an additional layer on top: FlowSR — Flow Signal Reconstruction. A machine-learning core that reconstructs network flows and derives device roles from incomplete traffic. Where the deterministic methods hit the wall, FlowSR fills the gaps.

FlowSR – Flow Signal Reconstruction From minimal flow data, FlowSR reconstructs six answers: device role, coarse and fine function, traffic shape, temporal context, and machine or human. MINIMAL INPUT NetFlow only or firewall only BYTES · DURATION · DIRECTION · PORT (± MAC / HOSTNAME) FLOW SIGNAL RECONSTRUCTION FlowSR reconstructs flows from incomplete traffic Device role 01 Function, coarse 02 Function, fine 03 Traffic shape 04 Temporal context 05 Machine / human 06 MAXIMUM FROM MINIMUM
DIAGRAM 01 Flow Signal Reconstruction: from minimal flow data — bytes, duration, direction, port — FlowSR reconstructs the answers that otherwise only costly deep inspection provides.

Six model families, six answers from raw flows

Device role

PLC, HMI/SCADA, engineering workstation, historian, network device or IT server — recognized by its communication fingerprint.

Function, coarse

Does a connection read values — or does it write and control?

Function, fine

Write value, program transfer, control command or configuration.

Traffic shape

Cyclic control, bulk transfer, request/response or data stream — regardless of the port in use.

Temporal context

Resolves ambiguous flow patterns via periodicity, volume profile and off-hours behavior.

Machine vs. human

Is there an automated process behind a connection, or a person at a keyboard?

The extension · Deep Analysis

Connections become process understanding.

FlowSR works in two layers: the six model families read each flow on its own — what the device is, what the connection does. The Deep Analysis layer reads the temporal sequence and the structure of the whole network above them — and answers what no single flow can answer.

Layer 2 · Deep Analysis

Sequence learning

the temporal order

Graph learning

the network structure

Fusion

both views combined

Layer 1 · Six model families

reads each flow on its own — role, function, shape, context, actor

DIAGRAM 02 Two layers: the model families interpret each flow on its own — the Deep Analysis layer reads sequence and network structure above them and combines both views.

Seven questions the Deep Analysis layer answers

Relationship purpose

Why does this connection exist in the process — control, monitoring, engineering, data storage?

Process phase

Which operating phase is the communication in — start-up, normal operation, intervention?

Asset role, coarse

The role assignment of the six families, confirmed from a second, independent view.

Asset role, fine

Finer-grained role profiles — which task a station takes on within the network.

Criticality

Which assets carry the process — a ranking derived from the communication structure.

Behavioral change

Has an asset changed its behavior compared with its own history?

Future relationships

Which communication relationships the plant will show next — the look ahead.

A connection becomes meaning. A bare connection becomes a verifiable interpretation: engineering workstation to PLC, program transfer, manual, outside the shift.

FlowSR as a semantic layer FlowSR sits as a semantic layer on top of the baseline, rule and process anomaly engines and turns an unusual connection into a finding that can be prioritized. SEMANTIC LAYER FlowSR What is the device? What does the flow do? 01 Baseline engine knows the normal state 02 Rule engine knows what is prohibited 03 Process anomalies knows the process EXISTING ENGINES · UNCHANGED “A connection is unusual” “Write access to a PLC” PRIORITIZABLE
DIAGRAM 03 FlowSR as a semantic layer above the unchanged engines — “unusual” becomes a finding that can be prioritized.

The principle: maximum from minimum. The leverage is greatest exactly where the least sensor coverage exists.

Where the platform comes into play.

In projects

Aganum uses the platform in visibility projects wherever it is the fastest route to a first situation picture. The result feeds directly into the decision basis: asset inventory, communication matrix, vulnerability overview, report.

Alongside established platforms

Our own platform does not replace a vendor-neutral recommendation: where Claroty, Nozomi, Dragos or another solution fits the plant better, that solution is recommended and deployed. The tool choice follows the plant — not our own product.

Access control

A platform inside a sensitive OT network must itself meet high demands: role-based login (RBAC), API tokens and a complete record of every single action — part of the design from the start.

Traceable

Every detection is explained and traceable back to the triggering event — no black box. That is exactly what makes the findings dependable.

Curious what this would look like in your plant?

Aganum is happy to show the platform in a live demonstration — and to discuss how passive OT network monitoring translates concretely to your environment.