Thieves seem to have a new gadget every week to skim your credit cards, hack into your accounts or steal your security codes. Now, they can even use your body heat to their advantage.

flir

Flir’s infrared iPhone case gives a handy thermal view of the world, but it gives would-be ATM pin thieves an upper hand (Image source: Flir).

A device that looks like an ordinary iPhone case can actually pick up the thermal heat signatures left behind after you punch in your bank code at the supermarket or the ATM.

The good news is there’s a creative — and simple — solution to thwart even the sneakiest attempts at thermal-assisted thievery. The best part? It doesn’t cost a thing.

This is how it works: a would-be ATM code thief buys a relatively inexpensive iPhone case with infrared-scanning capabilities. Thermal imaging used to be bulky and expensive or typically reserved for complex military operations, but now can be attained by nefarious types for just a few hundred dollars.

If they have the technology, a crook can simply walk up to a keypad you’ve just put your PIN into. They barely have to lift a finger — just their phones.

The thermal imaging camera will capture an image of the heat left behind after your fingers touched the buttons to put in your PIN. Using the intensity of the thermal signature, they can easily tell the order you punched the numbers in.

thermal signature

Image source: YouTube

This might not sound like too much of a concern; after all, even if the thief gets your PIN, if they don’t have the physical card they can’t cause too much damage, right?

Wrong. If the thief has devised a plan to snag your PIN, he or she likely has a way to capture the rest of your card’s information as well. It gets especially easy for the bad guys if you have a contactless card: something as simple as a radio frequency identification scanner (which work from up to three feet away in some cases) can capture your card’s data, and boom: The perp has all the info they need.

Mark Rober, a design and science guru, outlines the unique security attack and the very simple protective measure you can take to outsmart this tech trick. The key? It’s all about the buttons you’re touching. Watch him explain it:

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