OT & IT Convergence: Defending the Industrial Attack Surface in 2025

In 2025, the boundary between IT and operational technology (OT) is more porous than ever. What once were siloed environments are now deeply intertwined—creating new opportunities for efficiency, but also a vastly expanded attack surface. For industrial, manufacturing, energy, and critical infrastructure operators, the stakes are high: disruption in OT is real-world damage, not just data loss.

PLC

This article lays out the problem space, dissecting how adversaries move, where visibility fails, and what defense strategies are maturing in this fraught environment.


The Convergence Imperative — and Its Risks

What Is IT/OT Convergence?

IT/OT convergence is the process of integrating information systems (e.g. ERP, MES, analytics, control dashboards) with OT systems (e.g. SCADA, DCS, PLCs, RTUs). The goal: unify data flows, enable predictive maintenance, real-time monitoring, control logic feedback loops, operational analytics, and better asset management.

Yet, as IT and OT merge, their worlds’ assumptions—availability, safety, patch cycles, threat models—collide. OT demands always-on control; IT is optimized for data confidentiality and dynamic architecture. Bridging the two without opening the gates to compromise is the core challenge.

Why 2025 Is Different (and Dangerous)

  • Attacks are physical now. The 2025 Waterfall Threat Report shows a dramatic rise in attacks with physical consequences—shut-downs, equipment damage, lost output. Waterfall Security Solutions

  • Ransomware and state actors converge on OT. OT environments are now a primary target for adversaries aiming for disruption, not just data theft. zeronetworks.com+2Industrial Cyber+2

  • Device proliferation, blind spots. The explosion of IIoT/OT-connected sensors and actuators means incremental exposures mount. Nexus+2IAEE+2

  • Legacy systems with little guardrails. Many OT systems were never built with security in mind; patching is difficult or impossible. SSH+2Industrial Cyber+2

  • Stronger regulation and visibility demands. Critical infrastructure sectors face growing pressure—and liability—for cyber resilience. Honeywell+2Fortinet+2

  • Maturing defenders. Some organizations are already reducing attack frequency through segmentation, threat intelligence, and leadership-driven strategies. Fortinet


Attack Flow: From IT to OT — How the Adversary Moves

Understanding attacker paths is key to defending the convergence.

  1. Initial foothold in IT. Phishing, vulnerabilities, supply chain, remote access are typical vectors.

  2. Lateral movement toward bridging zones. Jump servers, VPNs, misconfigured proxies, flat networks let attackers pivot. Industrial Cyber+2zeronetworks.com+2

  3. Transit through DMZ / industrial demilitarized zones. Poorly controlled conduits allow protocol bridging, data transfer, or command injection. iotsecurityinstitute.com+2Palo Alto Networks+2

  4. Exploit OT protocols and logic. Once in the OT zone, attackers abuse weak or proprietary protocols (Modbus, EtherNet/IP, S7, etc.), manipulate command logic, disable safety interlocks. arXiv+2iotsecurityinstitute.com+2

  5. Physical disruption or sabotage. Alter sensor thresholds, open valves, shut down systems, or destroy equipment.

Because OT environments often have weaker monitoring and fewer detection controls, malicious actions may go unnoticed until damage occurs.


The Visibility & Inventory Gap

You can’t protect what you can’t see.

  • Publicly exposed OT devices number in the tens of thousands globally—many running legacy firmware with known critical vulnerabilities. arXiv

  • Some organizations report only minimal visibility into OT activity within central security operations. Nasstar

  • Legacy or proprietary protocols (e.g. serial, Modbus, nonstandard encodings) resist detection by standard IT tools.

  • Asset inventories are often stale, manual, or incomplete.

  • Patch lifecycle data, firmware versions, configuration drift are poorly tracked in OT systems.

Bridging that visibility gap is a precondition for any robust defense in the converged world.


Architectural Controls: Segmentation, Microperimeters & Zero Trust for OT

You must treat OT not as a static, trusted zone but as a layered, zero-trust-aware domain.

1. Zone & Conduit Model

Apply segmentation by functional zones (process control, supervisory, DMZ, enterprise) and use controlled conduits for traffic. This limits blast radius. iotsecurityinstitute.com+2Palo Alto Networks+2

2. Microperimeters & Microsegmentation

Within a zone, restrict east-west traffic. Only permit communications justified by policy and process. Use software-defined controls or enforcement at gateway devices.

3. Zero Trust Principles for OT

  • Least privilege access: Human, service, and device accounts should only have the rights they need to perform tasks. iotsecurityinstitute.com+1

  • Continuous verification: Authenticate and revalidate sessions, devices, and commands.

  • Context-based access: Enforce access based on time, behavior, process state, operational context.

  • Secure access overlays: Replace jump boxes and VPNs with secure, isolated access conduits that broker access rather than exposing direct paths. Industrial Cyber+1

4. Isolation & Filtering of Protocols

Deep understanding of OT protocols is required to permit or deny specific commands or fields. Use protocol-aware firewalls or DPI (deep packet inspection) for industrial protocols.

5. Redundancy & Fail-Safe Paths

Architect fallback paths and redundancy such that the failure of a security component doesn’t cascade into OT downtime.


Detection & Response in OT Environments

Because OT environments are often low-change, anomaly-based detection is especially valuable.

Anomaly & Behavioral Monitoring

Use models of normal process behavior, network traffic baselines, and device state transitions to detect deviations. This approach catches zero-days and novel attacks that signature tools miss. Nozomi Networks+2zeronetworks.com+2

Protocol-Aware Monitoring

Deep inspection of industrial protocols (Modbus, DNP3, EtherNet/IP, S7) lets you detect invalid or dangerous commands (e.g. disabling PLC logic, spoofing commands).

Hybrid IT/OT SOCs & Playbooks

Forging a unified operations center that spans IT and OT (or tightly coordinates) is vital. Incident playbooks should understand process impact, safe rollback paths, and physical fallback strategies.

Response & Containment

  • Quarantine zones or devices quickly.

  • Use “safe shutdown” logic rather than blunt kill switches.

  • Leverage automated rollback or fail-safe states.

  • Ensure forensic capture of device commands and logs for post-mortem.


Patch, Maintenance & Change in OT Environments

Patching is thorny in OT—disrupting uptime or control logic can have dire consequences. But ignoring vulnerabilities is not viable either.

Risk-Based Patch Prioritization

Prioritize based on:

  1. Criticality of the device (safety, control, reliability).

  2. Exposure (whether reachable from IT or remote networks).

  3. Known exploitability and threat context.

Scheduled Windows & Safe Rollouts

Use maintenance windows, laboratory testing, staged rollouts, and fallback plans to apply patches in controlled fashion.

Virtual Patching / Compensating Controls

Where direct patching is impractical, employ compensating controls—firewall rules, filtering, command-level controls, or wrappers that mediate traffic.

Vendor Coordination & Secure Updates

Work with vendors for safe update mechanisms, integrity verification, rollback capability, and cryptographic signing of firmware.

Configuration Lockdown & Hardening

Disable unused services, remove default accounts, enforce least privilege controls, and lock down configuration interfaces. Industrial Cyber


Operating in Hybrid Environments: Best Practices & Pitfalls

  • Journeys, not Big Bangs. Start with a pilot cell or site; mature gradually.

  • Cross-domain teams. Build integrated IT/OT guardrails teams; train OT engineers with security awareness and IT folk with process sensitivity. iotsecurityinstitute.com+2Secomea+2

  • Change management & governance. Formal processes must span both domains, with risk acceptance, escalation, and rollback capabilities.

  • Security debt awareness. Legacy systems will always exist; plan compensating controls, migration paths, or compensating wrappers.

  • Simulation & digital twins. Use testbeds or digital twins to validate security changes before deployment.

  • Supply chain & third-party access. Strong control over third-party remote access is essential—no direct device access unless brokered and constrained. Industrial Cyber+2zeronetworks.com+2


Governance, Compliance & Regulatory Alignment

  • Map your security controls to frameworks such as ISA/IEC 62443NIST SP 800‑82, and relevant national ICS/OT guidelines. iotsecurityinstitute.com+2Tenable®+2

  • Develop risk governance that includes process safety, availability, and cybersecurity in tandem.

  • Align with critical infrastructure regulation (e.g. NIS2 in Europe, SEC cyber rules, local ICS/OT mandates). Honeywell+1

  • Build executive visibility and metrics (mean time to containment, blast radius, safety impact) to support prioritization.


Roadmap: From Zero → Maturity

Here’s a rough maturation path you might use:

Phase Focus Key Activities
Pilot / Awareness Reduce risk in one zone Map asset inventory, segment pilot cell, deploy detection sensors
Hardening & Control Extend structural defenses Enforce microperimeters, apply least privilege, protocol filtering
Detection & Response Build visibility & control Anomaly detection, OT-aware monitoring, SOC integration
Patching & Maintenance Improve security hygiene Risk-based patching, vendor collaboration, configuration lockdown
Scale & Governance Expand and formalize Extend to all zones, incident playbooks, governance models, metrics, compliance
Continuous Optimization Adapt & refine Threat intelligence feedback, lessons learned, iterative improvements

Start small, show value, then scale incrementally—don’t try to boil the ocean in one leap.


Use Case Scenarios

  1. Remote Maintenance Abuse
    A vendor’s remote access via a jump host is compromised. The attacker uses that jump host to send commands to PLCs via an unfiltered conduit, shutting down a production line.

  2. Logic Tampering via Protocol Abuse
    An attacker intercepts commands over EtherNet/IP and alters setpoints on a pressure sensor—causing shock pressure and damaging equipment before operators notice.

  3. Firmware Exploit on Legacy Device
    A field RTU is running firmware with a known remote vulnerability. The attacker exploits that, gains control, and uses it as a pivot point deeper into OT.

  4. Lateral Movement from IT
    A phishing campaign generates a foothold on IT. The attacker escalates privileges, accesses the central historian, and from there reaches into OT DMZ and onward.

Each scenario highlights the need for segmentation, detection, and disciplined control at each boundary.


Checklist & Practical Guidance

  • ⚙️ Inventory & visibility: Map all OT/IIoT devices, asset data, communications, and protocols.

  • 🔒 Zone & micro‑segment: Enforce strict controls around process, supervisory, and enterprise connectivity.

  • ✅ Least privilege and zero trust: Limit access to the minimal set of rights, revalidate often.

  • 📡 Protocol filtering: Use deep packet inspection to validate or block unsafe commands.

  • 💡 Anomaly detection: Use behavioral models, baselining, and alerts on deviations.

  • 🛠 Patching strategy: Risk-based prioritization, scheduled windows, fallback planning.

  • 🧷 Hardening & configuration control: Remove unused services, lock down interfaces, enforce secure defaults.

  • 🔀 Incident playbooks: Include safe rollback, forensic capture, containment paths.

  • 👥 Cross-functional teams: Co-locate or synchronize OT, IT, security, operations staff.

  • 📈 Metrics & executive reporting: Use security KPIs contextualized to safety, availability, and damage containment.

  • 🔄 Continuous review & iteration: Ingest lessons learned, threat intelligence, and adapt.

  • 📜 Framework alignment: Use ISA/IEC 62443, NIST 800‑82, or sector-specific guidelines.


Final Thoughts

As of 2025, you can’t treat OT as a passive, hidden domain. The convergence is inevitable—and attackers know it. The good news is that mature defense strategies are emerging: segmentation, zero trust, anomaly-based detection, and governance-focused integration.

The path forward is not about plugging every hole at once. It’s about building layered defenses, prioritizing by criticality, and evolving your posture incrementally. In a world where a successful exploit can physically damage infrastructure or disrupt a grid, the resilience you build today may be your strongest asset tomorrow.

More Info and Assistance

For discussion, more information, or assistance, please contact us. (614) 351-1237 will get us on the phone, and info@microsolved.com will get us via email. Reach out to schedule a no-hassle and no-pressure discussion. Put out 30+ years of OT experience to work for you! 

 

 

* AI tools were used as a research assistant for this content, but human moderation and writing are also included. The included images are AI-generated.

Enabling ESP32 Secure Boot

What is Secure Boot?

ESP32 has a secure boot feature that allows you to configure the device to only accept signed firmware images from trusted sources. This can be used to prevent unauthorized modifications of your code and data on the ESP32, or to protect against malicious software (malware) attacks.

Why should it be used?

The ESP32 is an open-source hardware platform, which means anyone can modify its design. However, this also makes it vulnerable to malware attacks. If the attacker gains access to the device’s flash memory, they could replace the original firmware with their own version. In addition, if the attacker manages to gain root access, they could install any software on the device without user consent.

Secure boot prevents these types of attacks by requiring all firmware images to be digitally signed before being loaded into the device. Only those images that are signed by a trusted certificate authority will be accepted.

How does it work?

The ESP32 uses a Trusted Platform Module (TPM), which is a special-purpose chip designed for cryptographic operations. It provides a tamper-resistant environment where sensitive information such as passwords, keys, and certificates can be stored securely.

When the ESP32 boots up, it reads the TPM’s public key and checks whether the image file is signed using the private key associated with the public key. If so, the image is loaded into the device. Otherwise, the system displays an error message and refuses to load the image.

How do I enable it?

Secure Boot is enabled by default in the latest version of Espressif’s SDK for ESP32 development. But, on older versions of the SDK, you need to set the “secure_boot” option when initializing the board:

esp_init(0, 0x000002ff); // Initialize ESP32 module at address 0x00000200

esp_set_secure_mode(1); // Set secure boot mode

 

Why You Should Support CS2AI

What is Control Systems Cyber Security Association International (CS2AI.org)?

The mission of the Control Systems Cyber Security Association, Inc. (CS2AI) is to promote and advance cyber security education, research, and practice to protect critical infrastructure and ensure the safety and reliability of our nation’s control systems.

What does that mean? It means we are here to help you understand how to keep your control system safe from hackers, malware, and other threats. We want to ensure you know what to look for in a good cybersecurity program and how to find it.

We also want to ensure you have access to the best resources available to help you stay up-to-date on current trends and technologies.

Why does MSI support it?

Because we believe in its mission. We believe in making sure everyone has access to the information they need to make informed decisions about their own cybersecurity programs, especially when it comes to ICS.

We believe in helping people learn more about cybersecurity so they can take steps toward protecting themselves and their organizations.

We believe in supporting those who share our passion for improving the world through technology. CS2AI supports the core mission of MSI – making the online world a safer place for all of us.

How do I get involved?

It’s simple – click here to learn more about joining and the benefits of supporting the ongoing efforts to improve global cyber security.

Why Emulate a PLC with a Raspberry Pi

One of the most powerful uses of emulating a PLC (Programmable Logic Controller) field device with a Raspberry Pi is that it provides an affordable and easily obtained platform for prototyping, performing ladder logic testing, and researching various industrial control systems and cybersecurity concepts.

Raspberry Pis are Affordable

Raspberry Pi models 3 and 4 are significantly more affordable than real PLCs. A typical PLC can cost hundreds or thousands of dollars.

The Raspberry Pi costs around $35-50 depending on your model choice. This makes them very accessible to hobbyists, students, researchers, developers, and anyone else who wants to work with the basics of industrial control systems. The low cost makes them ideal candidates to emulate a PLC in many scenarios.

Raspberry Pis are Easily Obtainable

PLCs can be quite difficult to come by, especially if you want one without any pre-existing software installed. Many manufacturers will not sell their products to third parties unless they have some kind of existing relationship. If you don’t already know someone at the manufacturer then you may need to pay a hefty upcharge. Additionally, purchasing the addons for power supplies, specific programming software, and such can quickly turn into a slog of paperwork and supporting tasks. The lead time and delivery times can take weeks to months.

The Raspberry Pi, on the other hand, can be purchased at many big-box electronics or computer stores, directly from many providers, or even delivered to your door from Amazon and other online sources. It uses a common USB power supply and can be configured and programmed using open source tools available online. Lead time is a couple of days to a few hours, letting you stay focused on your work.

The OpenPLC Project

The OpenPLC Project is a stable, well-documented toolkit for emulating basic PLC operations on the Pi. It has been used successfully to simulate a variety of different types of PLCs and includes support for ladder logic and other common PLC functions. You can find the programming reference and review the available capabilities here.

You can get OpenPLC up and running on a Pi in less than 30 minutes. In our testing, we were able to begin using the emulated PLC in our lab within an hour!

Going The Extra Mile With SCADABR

SCADABR is an open-source supervisory control and data acquisition software package designed to allow you to create interactive screens or human-machine interfaces (HMI) for your automation projects. It provides tools for creating graphical user interface widgets, event handlers, timers, and dialogs. With its ability to communicate with multiple controllers (including OpenPLC), ScadaBR is an ideal companion for the OpenPLC Runtime and Editor.

Using a Pi, OpenPLC, and SCADABR together, can get you a very powerful and useful PLC platform up and running for under $100 and in less than a few hours. Once implemented, you can use the platform to learn about industrial controls systems, ladder logic, PLC programming, and operations. You can also do basic ladder logic research and testing, and even prototyping for future real-world PLC deployments. Cybersecurity folks also have a very capable platform for learning about industrial control security requirements, performing vulnerability research, reverse engineering, or practicing their assessment skills in a safe environment.

While you might not get the full power of a true PLC (there are some limitations to Pi’s capabilities), you will likely get more than you expect. If you have an interest in or a need for some basic industrial control systems capabilities, this is a great place to start.

 

 

IT/OT Convergence and Cyber-Security

Today, I spoke at ComSpark as a part of a panel with Chris Nichols from LucidiaIT and David Cartmel from SMC. 

We talked extensively about convergence and the emerging threats stemming from the intertwined IT/OT world. 

If you missed it, check the ComSpark event page here. I believe they are making some of the content available via recording, though a signup might be required. 

Our virtual booth also had this excellent video around the topic. Check it out here.

Thanks and hit me up on Twitter (@lbhuston) and let me know your thoughts.

Saved By Ransomware Presentation Now Available

I recently spoke at ISSA Charlotte, and had a great crowd via Zoom. 

Here is the presentation deck and MP3 of the event. In it, I shared a story about an incident I worked around the start of Covid, where a client was literally saved from significant data breach and lateral spread from a simple compromise. What saved them, you might ask? Ransomware. 

That’s right. In this case, ransomware rescued the customer organization from significant damage and a potential loss of human life. 

Check out the story. I think you’ll find it very interesting. 

Let me know if you have questions – hit me up the social networks as @lbhuston.

Thanks for reading and listening! 

Deck: https://media.microsolved.com/SavedByRansomware.pdf

MP3: https://media.microsolved.com/SavedByRansomware.mp3

PS – I miss telling you folks stories, in person, so I hope you enjoy this virtual format as much as I did creating it! 

An Exercise to Increase IT/OT Engagement & Cooperation

Just a quick thought on an exercise to increase the cooperation, trust and engagement between traditional IT and OT (operational technology – (ICS/SCADA tech)) teams. Though it likely applies to just about any two technical teams, including IT and development, etc.

Here’s the idea: Host a Hack-a-thon!

It might look something like this:

  • Invest in some abundant kits of LittleBits. These are like Legos with electronics, mechanical circuits and even Arduino/Cloud controllers built in. Easy, safe, smart and fun!
  • Put all of the technical staff in a room together for a day. Physically together. Ban all cell phones, calls, emails, etc. for the day – get people to engage – cater in meals so they can eat together and develop rapport
  • Split the folks into two or more teams of equal size, mixing IT and OT team members (each team will need both skill sets – digital and mechanical knowledge) anyway.
  • Create a mission – over the next 8 hours, each team will compete to see who can use their smart bits set to design, program and proto-type a solution to a significant problem faced in their everyday work environments.
  • Provide a prize for 1st and 2nd place team. Reach deep – really motivate them!
  • Let the teams go through the process of discussing their challenges to find the right problem, then have them use draw out their proposed solution.
  • After lunch, have the teams discuss the problems they chose and their suggested fix.Then have them build it with the LittleBits. 
  • Right before the end of the day, have a judging and award the prizes.

Then, 30 days later, have a conference call with the group. Have them again discuss the challenges they face together, and see if common solutions emerge. If so, implement them.

Do this a couple times a year, maybe using something like Legos, Raspberry Pis, Arduinos or just whiteboards and markers. Let them have fun, vent their frustrations and actively engage with one another. The results will likely astound you.

How does your company further IT/OT engagement? Let us know on Twitter (@microsolved) or drop me a line personally (@lbhuston). Thanks for reading! 

ICS/SCADA Security Symposium 2014 Announced

For those of you who were wondering about our yearly event, the 4th annual ICS/SCADA Security Symposium has been announced!

The date will be Thursday, December 11, 2014 and the entire event will be virtual! Yes, that’s right, no travel & no scheduling people to cover the control room. YOU can learn from right there! 

To learn more about the event, the schedule and to register, click here!

Save The Date: 2014 ICS/SCADA Security Symposium Dec. 11

This year’s ICS/SCADA Security Symposium will be held on Thursday, December 11, 2014. This year’s event will be a little different, in that we are opening it up to any organizations who are asset owners or manufacturers of ICS/SCADA components. That includes utilities, manufacturing companies, pharma, etc. If you are interested in ICS security, you can sign up for the event.

This year’s event will also be virtual. It will be a series of Webinars held on the same day in 45 minute blocks, with time for follow-on questions. We will also hold a Twitter Q&A Hour from 1pm – 2pm Eastern, and we will attempt to make all speakers available for the Q&A!

In addition, we plan to stand up a supporting website for the event, and release a number of materials, including podcasts, interviews and other surprises the day of the event!

We will be tracking attendance in the webinars and providing notes of attestation for attendees for the purpose of CPE credits. We hope this new format will allow folks who wanted to attend in the past, but either couldn’t make the physical trip to Columbus or couldn’t leave their positions to attend training the ability to join us.

More details, including speakers and topics, as well as schedules, hashtags and other info will be released shortly. Thanks for reading, and we hope to see you on 12/11/14!

Co-Op & Municipal Utilities Get Discounts in July

Attention Co-Op & Municipal utilities — MSI is offering discounts to your organizations on professional services (policy/process, assessments, pen-testing, etc.), lab services (device & AMR/AMI assessments, threat assessments, etc.) and HoneyPoint Security Server for the month of July. Book the business before July 31’st and have the work/implementation completed before December 31st of 2014 and you receive a discount up to 30% off!

Do you need pen-testing against your business network? Need web app assessments on billing or payment systems? Have a call for risk assessments, smart grid device testing or fraud testing against your meters and field gear? All of this and more qualifies!

Check out our ICS/SCADA specific services by clicking here!

Give Allan Bergen a call today at 513-300-0194 to learn more about our program. We truly appreciate the hard work and dedication that Co-op and Municipal utility teams do, and we look forward to working with you!