How to Manage USB-Based Threats in Field Operations

In energy and utility sectors, USB drives remain a practical necessity. Field engineers operate in remote substations, generation plants, and distribution points where network connectivity is limited or deliberately unavailable. Configuration updates, diagnostics, firmware packages, and log collection often rely on removable media. Despite longstanding awareness of USB-related malware, unmanaged USB use remains one of the most persistent cyber risks in operational technology networks.

The issue is not the existence of USB drives. The problem is that they are still used without regular checks, oversight, or accountability. In OT field operations, a single infected USB device can quietly introduce malware into systems that are designed to remain isolated, stable, and predictable.

USB Usage Is Embedded in Field Operations

Field work in energy systems rarely resembles controlled office environments. Engineers and technicians routinely rely on USB devices to perform tasks such as:

• Uploading PLC logic and configuration files

• Applying firmware updates to protection relays

• Extracting logs and diagnostics from field equipment

• Updating HMI screens or historian configurations

• Performing vendor-driven maintenance activities

• Troubleshooting incidents under time pressure

Many of these environments are intentionally air-gapped, while others are only connected intermittently. In both scenarios, USB remains the primary method of transfer. Completely removing USB from these workflows is often impractical. The risk emerges when this necessity is not matched with an architecture capable of controlling what enters sensitive OT networks through removable media.

Why USB-Based Attacks Are More Dangerous in OT Networks

USB-based threats act differently in OT networks compared to IT networks. In office networks, a compromised USB might trigger endpoint alerts or be isolated rapidly. In field environments, detection takes longer and the consequences are more extensive.

OT devices often run legacy operating systems or embedded firmware that can't support modern endpoint protection. Once malware enters these systems, it can remain hidden for long periods without being detected. Engineering laptops, which frequently move between sites, can unintentionally spread the same threat across substations or facilities.

More importantly, OT malware does not need to exfiltrate data to cause damage. It can disrupt protection logic, interfere with process control, or weaken confidence in system integrity. In energy systems, even small deviations can force operators to halt operations to ensure safety. The impact is operational disruption, not just a cybersecurity incident.

Field Engineers as Unintentional Risk Bridges

USB-based cyber risks in the field are often framed as human factor problems. In reality, they highlight a workflow problem.

Field engineers work under pressure. Maintenance windows are brief. Outages are expensive. When a task requires a file transfer, engineers rely on the tools available. USB drives are reused at different sites. Vendor-supplied media is trusted by default. Laptops gather tools, drivers, and files over time.

These practices are not reckless; they are practical responses to operational demands. However, without cybersecurity architectural controls, they create invisible bridges between isolated systems. A USB device used at one compromised site can easily introduce malware into another, even if both environments are otherwise well protected.

Blaming individuals doesn't lower this risk. Designing workflows that assume USB will be used and managing it accordingly does.

The Real Consequences of USB-Based Incidents

USB-based compromises in OT environments rarely announce themselves immediately. Instead, they surface through secondary effects:

• Unexpected behavior in protection systems

• Configuration drift with no clear source

• Engineering workstation instability

• Loss of trust in system state

• Emergency shutdowns to assess impact

• Regulatory scrutiny following preventable incidents

In critical infrastructure, uncertainty can be just as harmful as confirmed compromise. When operators cannot be confident that systems are secure, they tend to make conservative operational choices that impact availability and reliability.

An Architectural Approach to USB Risk Management

Most organizations already have USB usage policies and often provide awareness training. However, USB-related incidents persist because policies do not align with real-world conditions.

USB bans are hard to enforce at remote sites. Field work cannot pause for centralized approvals. Antivirus on laptops does not safeguard PLCs, relays, or embedded devices. Manual file checks are often skipped when time is limited. Logging and traceability are frequently absent once engineers leave the site.

Managing USB-based threats in OT requires shifting from prohibition to control. This means designing an architecture where USB use is expected but considered untrusted by default.

Key principles include:

• Centralized inspection of all files before they enter OT environments

• Sanitization to remove hidden payloads, scripts, or malformed content

• Separation between field media and operational systems

• One-directional workflows that prevent cross-contamination

• Clear audit trails linking files to tasks, sites, and timeframes

• Processes that engineers can follow without slowing down work

This approach treats USB as a controlled ingress point, not a blind spot. The result is not restricted operations, but resilient ones built on predictable, enforceable control.

Making USB Devices Safe for Field Operations with DataStationX

In field operations, USB drives are unavoidable. What is avoidable is the assumption that they are safe.

DataStationX by DataFlowX, a secure media transfer station, addresses this gap by turning USB usage into a controlled, inspectable, and auditable process. It prevents malware embedded in configuration files or firmware packages from reaching OT systems, stops cross-site contamination carried by reused media, and ensures that only validated content enters sensitive environments.

By aligning security controls with how field work actually happens, DataStationX enables engineers to perform critical tasks without introducing silent risks into operational networks.

Contact our expert team today to see how you can unlock safe and secure OT field operations.