OT, ICS & SCADA Penetration Testing

We start on paper and diagrams. We map your zones and conduits against the Purdue model and IEC 62443, identify where enterprise IT touches OT, and work out the most likely route an attacker takes: a phished engineer, a flat network, a forgotten vendor VPN, an internet-exposed HMI. That map tells us where testing effort actually reduces risk.

On the control network we begin by listening. Passive traffic analysis identifies the devices, protocols and communication patterns present without sending a single risky packet. This alone frequently surfaces serious issues: unencrypted control traffic, unexpected internet connectivity, rogue devices, and protocols in use that nobody documented.

With scope and safety agreed, we move to active work at the IT-to-OT boundary and against non-production or resilient assets. We test whether segmentation actually holds, whether an attacker on the business network can reach control systems, and whether device and protocol authentication stands up. Anything that could affect a live process is either run in your test environment or scheduled into a maintenance window with your team present.

Findings come as an executive summary for leadership and plant management and a technical report for engineering and OT security. Each finding has an impact rating in operational terms, reproduction detail, and a remediation that respects how hard OT change is. After you remediate, we retest for free within the same safety constraints.

The single most common finding is that the boundary between IT and OT is thinner than the network diagram claims. A firewall exists but permits far more than it should, a management VLAN bridges both worlds, or a dual-homed workstation quietly connects them. Once inside IT, an attacker reaches control systems with little resistance. We prove whether that path is real.

Modbus, DNP3 and their peers were built for trusted networks and often carry no authentication or encryption at all. An attacker on the control network can read process values and, worse, issue commands to controllers. We assess where these protocols run exposed and what an attacker could do with access to them.

Vendor VPNs left permanently open, remote-access tools installed for a maintenance job and never removed, and shared engineering credentials are a favourite entry point. Many real ICS incidents began with legitimate remote access, not an exotic exploit. We hunt these paths down and test how far each one reaches.

HMIs reachable from the internet, historians with default credentials, and PLCs running firmware years behind on patches are routine. Patching OT is genuinely hard, so we focus on compensating controls and isolation rather than pretending you can simply update everything overnight.

The core standard for industrial automation and control system security. We frame findings in its language of zones, conduits and security levels, so your team and any assessor can place each one in the model you already work to.

The established guide to securing operational technology. Where you report to a framework built on it, we map findings accordingly and keep recommendations consistent with its guidance.

For operators of essential and important services across Europe, NIS2 raises the bar on risk management and incident readiness. Our testing evidence and report support your obligations, and we are a European team that understands how these requirements are being applied across member states.

The first foothold is usually a phished credential, an exposed remote-access service, or a vulnerable internet-facing application on the corporate side. None of that is exotic, and none of it touches a PLC yet. This is why the IT estate and its people are part of a serious OT assessment, not a separate concern.

From IT, the attacker looks for the path to OT: a firewall rule that is too permissive, a dual-homed engineering workstation, a jump host with weak controls, or a management network that quietly spans both. The strength of this boundary is the single biggest factor in whether an IT compromise ever becomes an OT one, so we spend disproportionate effort proving whether it holds.

Only once inside the control network does the attacker interact with HMIs, historians and controllers, often using entirely legitimate protocol commands because the protocols themselves ask for no proof of identity. By the time we are testing this stage, the point is usually already made: if the earlier steps succeed, the process is exposed. We demonstrate that chain end to end, safely, rather than leaving you to assume it.