Operational Technology (OT) Security: Protecting Critical Infrastructure

It’s 8:15 p.m., and I’m on my third coffee — but this blog seems necessary. The professionalism of OT security is growing, and about time too. I’ve been on cyber for long enough to watch trends wax and wane in time — OT security is not one of those fads. And it’s crucial, particularly for fields such as manufacturing where a single mistake can halt a whole factory floor — or worse, an entire supply chain — dead in its tracks. Let’s dig into this.

Introduction

I’ve been doing this since 1993. Back when dial-up connections dominated the planet and we believed token-ring networks were groundbreaking. Zoom forward to now, and I have just finished assisting three banks with a complete overhaul of their zero-trust architecture. And boy, let me tell you — it’s a jungle out there, particularly in the OT space. Manufacturing, energy, utilities, you name it. Industries that used to be proud of being insulated by old-school systems and manual work are now leaping into some kind of connected networks. And connectedness brings danger as well.

It is fascinating (and somewhat terrifying) how many businesses still believe that OT and IT security are the same beast. Spoiler: They’re not. I have witnessed global manufacturing companies where the measures taken to protect an ageing CNC machine were worlds apart from the ones taken to protect their email servers. If we’ve learned anything in the last 30 years of digital evolution, it’s this: what works for your IT, will not work for your OT.

OT vs. IT Security

The fact is this — OT systems were never built for security. They were largely uptime and reliability focused. And they’ve done that quite well. But once we started bridging OT with IT environments — because who doesn’t love a little IoT magic? — we invited hackers to the party.

• IT Security involves protecting data — emails, business documents, customer information. Think firewalls, endpoint security, and virtual private networks, or VPNs.
• OT Security correlates to physical processes—assembly lines, robotic arms, cooling towers. Any breach here doesn’t merely play with data — it could halt production or cause real-world damage.

Not to mention the vastly different lifecycles. Typically the average IT system has a refresh cycle of a few years. Some OT systems? They have been running on the same software since the early 2000s (and sometimes even before I dealt with the Slammer worm crisis). If it’s not broken, why fix it, right? At least not when it’s full of security holes.

Common Vulnerabilities

As someone who has worked with OT systems — especially in the areas of manufacturing — I understand that their vulnerabilities can be staggering and distinct. Some haunt me every time I walk through a factory floor.

1. Legacy Systems

The majority of OT environments are full of legacy tech. Why? Because replacing them is costly and disruptive. Some plants still have operating systems dating from Windows XP to even DOS-based systems (yes, really). These machines were never meant to handle the type of threats we’re experiencing today.

2. Lackluster or Absent Authentication

You’d be amazed how many OT devices are still using default passwords such as “admin” or “1234.” I’ve gone into facilities where the operators didn’t even know passwords could be changed. This is hacker gold.

3. Lack of Network Segmentation

What if OT and IT are located on the same flat network? Big problem. Malware slithering from a hacked email server to vital plant gear is faster than I can pound down my first espresso. And don’t even get me started on the number of times I’ve seen industrial systems present on the internet as-is.

4. Vendor Backdoors

What many OT systems are equipped with, however, is a built-in maintenance backdoor. These were ancillary services but can make for low-hanging fruit — particularly where vendors don’t secure them correctly (or tell the client they even exist).

Best Practices for OT Security

Enough doom and gloom. There are ways to stay ahead of these vulnerabilities. You don’t have to scrap all your infrastructure immediately, but a few pointed steps can have a big impact.

1. Network Segmentation

Treat your OT network like your grandma’s fine china; don’t let just anyone touch it. Keep your IT and OT environments separate behind hardened firewalls and air-gap them if you can. Without an obvious pathway for malware, it’s much more difficult to exploit.

2. Update (Where Possible)

Updates in OT are a very messy business I know. Downtime is expensive, and a lot of devices weren’t built to be patched. But you need to act on critical patches ahead of others — especially devices connected to or accessible from external networks.

3. Implement Multi-Factor Authentication (MFA)

One of the easiest methods to ensure security is by decentralizing access by implementing MFA to all your accounts. If you are dependent on single passwords for securely accessing remote login or admin accounts, then you’re basically giving attackers the keys to your kingdom. Use MFA wherever possible.

4. Conduct Regular Audits

When was the last time invasive testing of your OT environment was conducted? Regular audits can uncover latent problems before they spiral into full-blown crises. And don’t only consider the tech — assess processes and staff training as well.

5. Incident Response Plans

No system is invulnerable. You are breached sooner or later. The key is how you handle it. Possess a clear incident response plan for your OT systems.

Future Trends

So let’s discuss what lies ahead. I just got back from DefCon, where the hardware hacking village had me geeking out like it was the early ‘90s again. The innovations — and exploits — they displayed using industrial controllers? Terrifying. But also enlightening.

1. Convergence of OT and IT

This trend is not going away. With the growing acceptance of Industry 4.0 (AI, IoT, predictive maintenance) in manufacturing, the borders between OT and IT will further fade. That makes for amazing efficiencies — but also for risks. Every device you connect increases your attack surface.

2. AI Overpromises

AI can assist with threat detection and response. But it isn’t a get-out-of-breach-free card. It is simply another tool in your toolbox.

3. The Rise of Ransomware in OT

Ransomware groups have turned their sights to OT. Why? Because they understand that downtime loses millions of dollars in business in industries such as automotive and electronics. If IT ransomware is bad, just think of freezing an entire assembly line till you cough up.

4. Hardware-Based Threats

Attacks have increasingly shifted towards hardware weaknesses in operational technology (OT) systems. These kinds of threats are harder to store in memory and patch than software-based exploits, which makes them an increasing threat.

Quick Take

Pressed for time? Here’s the TL;DR:

• OT ≠ IT. So: different systems, different risks, different solutions.
• Adopt network segmentation. Keep your OT as well as you can in a box.
• Don’t skip out on patches and MFA for OT systems, even if they’re ancient.
• Stay ready — regularly audit and have a customized incident response plan in place.
• Future threats such as AI hype and hardware exploits are at the door. Stay ahead.

This isn’t about perfection in cybersecurity. It’s about resilience building. OT systems may seem like a blast from the past (and some of them are), but they’re also the lifeblood of modern industry. Be kind to them, give them the respect and the care they deserve, because once they’re down it’s not just a digital inconvenience, it’s a real-world disaster.