In the world of industrial operations, whether it’s a factory floor, an energy plant, or a logistics hub, most conversations about security tend to focus on OT—air gaps, firewalls, patch windows, vendor access, and similar essentials. While all of these are important, there’s a reality that often gets overlooked: your OT environment is only as secure as your IT environment.

This isn’t just a catchy phrase. In nearly every incident I’ve seen or helped resolve, attackers don’t usually begin with a PLC or a SCADA system. They almost always find the weakest link on the IT side.

The Door Might Already Be Open

Think about a compromised cloud account, a forgotten jump box exposed to the internet, or a contractor’s laptop with saved credentials. These are often the entry points. Once inside, attackers can quickly pivot to the OT network, especially when IT hygiene has been neglected. That cloud dashboard connected to your telemetry, the VPN engineers use to reach the plant, or the RDP server exposed during the pandemic—these are all real attack surfaces.

What Does Good IT Hygiene Actually Mean?

Forget best practice checklists for a moment. Here’s what truly matters when it comes to protecting your operations.

1. Lock Down Identity First

Multi-factor authentication is a must. If anyone can reach the OT environment without MFA, that’s a gap that needs to be closed.
Apply least privilege across the board, meaning nobody should have domain admin rights for everyday work.
Consider tools like Privileged Identity Management, which allow you to grant temporary elevated access instead of giving out standing high-level permissions.

2. Harden Every Connection to OT

Any IT system that bridges to OT—like jump hosts, historian servers, or analytics dashboards—should be treated as critical.
Keep these systems updated, protected by endpoint detection and response, and monitored carefully.
Anything that connects both sides is valuable to you, but it’s even more valuable to an attacker.

3. Know What’s Connected

Surprisingly, many organizations don’t have a complete list of what’s actually talking to OT.
Segment your networks, put firewalls and allowlists in place, and inspect traffic between different zones.
Tools like Microsoft Defender for IoT or other network monitoring solutions can provide the visibility you need.

4. Remove Legacy Access

If you have old TeamViewer access, RDP without MFA, or stopgap solutions from the pandemic still active, those are risks.
Remote access needs to be managed, monitored, and secured.
Modernize your remote access strategy, make sure everything is logged, and treat vendor access as a privilege, not an open door.

5. Don’t Overlook the Cloud

OT environments are more connected to cloud dashboards, telemetry APIs, and analytics tools than ever.
Make sure these cloud services follow the same IT hygiene rules—MFA, RBAC, secure development, and audit trails.
A weak link in your cloud pipeline can still cause disruption on the plant floor.

IT and OT Should Work Together

Attackers see your IT and OT environments as a single target, and you should, too.
If your security and OT teams only talk during incidents, you’re already behind.
Encourage ongoing collaboration, share insights, practice tabletop scenarios, and get clear on what normal looks like and who is responsible for what.

Final Thought

Many organizations have invested heavily in OT segmentation, firewalls, and vendor access tools, and that’s all necessary. But none of it is enough if attackers can still walk right through the IT front door.
Focus on cleaning up identity sprawl, hardening your endpoints, and segmenting your networks. When it comes to protecting your operations, strong IT hygiene isn’t just a best practice, it’s essential.