The Holiday Ambush: The One Thing Every OT CISO Is Telling Me This December

I’ve been on back-to-back calls for the last two weeks; Q4 is always a sprint. But amid budget negotiations and 2026 planning, I noticed a very specific, quiet anxiety emerging in nearly every conversation I had with OT leaders and CISOs.

It wasn't about compliance audits. It wasn't even about the budget we were finalizing.

It was about the calendar.

I was speaking with a Director of Operations at a regional water utility yesterday, and he said it point-blank: "Vince, I have three guys covering the plant from Christmas Eve to New Year's. If something hits us, then we aren't stopping it until it's too late."

He’s not paranoid. He’s looking at the data. And if you look at the history of the most devastating OT attacks, you’ll see he is exactly right to be worried.

The "Holiday Ambush" is Real

Hackers run their operations like businesses. They have P&Ls, org charts, and a calendar. They know exactly when your skeleton crew is on shift.

We talk a lot about technical vectors, but we rarely talk about timing. When we were compiling the data for our "Infamous Hacks" report, the dates jumped off the page:

• Ukraine Power Grid: The lights went out on December 23, 2015. Right when everyone was ready to clock out for the holidays.
• Colonial Pipeline: Hit on May 7, 2021. That was Mother's Day weekend.
• JBS Foods: The breach occurred on May 30, 2021. That was Memorial Day weekend.
• Kaseya VSA: The supply chain attack that hit thousands of MSPs launched on July 2, 2021. Just in time for the Fourth of July.

This isn’t a coincidence. It is a tactical decision by the enemy to strike when your "Human Firewall" is at its weakest.

Why "Detection" Fails the Holiday Test

The customer I spoke to yesterday has spent a fortune on detection tools. But here is the problem he realized: Detection relies on reaction.

Detection tools are essentially alarm bells. They are great (if someone is awake, alert, and within running distance of the control panel to hear them). But on December 25th? Or at 2:00 AM on New Year's Day?

You are betting your entire infrastructure on a junior analyst noticing an anomaly while half the company is out of the office. That is a bet the attackers are willing to take every single time.

Buy Yourself Some Peace of Mind

This is why the conversations I’m having this month are shifting so heavily toward Prevention.

When I explain Network Cloaking to these executives, the reaction is almost physical relief. They realize that if the asset is invisible, they don't need a fully staffed SOC to stare at it 24/7.

A gateway that cloaks your control systems doesn't take holidays. It doesn't get "alert fatigue." It doesn't get distracted by holiday travel. It simply rejects any connection that doesn't have the right key. It effectively removes the "When" from the attacker's equation.

If you are heading into this holiday break worrying about your remote access ports, you aren't alone. Every CISO I know is thinking about it. But you don't have to just hope for the best. 

May your holiday be peaceful and hack-free.

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— Vince Zappula, CRO, BlastWave