US scientists are warning that the technology is more advanced than traditional ATM fraud techniques and it is likely to be the next threat for this form of crime.
Researchers at the University of California at San Diego found that up to 45 seconds after a person types their pin code into an ATM machine or door entry pad the numbers and even the sequence are still readable by thermal cameras.
Experts have warned the worrying tactic has not become widely used only due to the cost of thermal imaging equipment - which start at around $1,200.
The thermal scam is said to be more advances than traditional ATM machine fraud techniques, which typically involve a thief attaching a card 'skimming' reader to the ATM machine along with a pinhole camera, strategically aimed at the key pad.
The skimmer records the ATM card details - which can then be transferred to another card - while the camera records the pin number sequence. But if the pin number is blocked by the person's hand, then the information taken by the skimmer is useless.
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