A middle-aged newspaper salesman in Buenos Aires, Argentina, was recently arrested for “hacking” dozens of credit cards and using them to make small purchases.

When crime-fighting authorities in Argentina received a complaint about hundreds of unauthorized purchases, they were sure they were dealing with an organized hacking group. However, all leads pointed to the house of a 56-year-old newspaper salesman in the Buenos Aires town of Villa Madero. Judging by the scale of the security breach, it seemed unlikely that one person, let alone one that operated a newspaper stand, could have pulled it off. And yet, upon searching the man’s house, they found a small notebook containing a hand-written algorithm that had apparently allowed him to figure out the CVC (Card Verification Code) of his victims.

Photo: Emil Kalibradov/Unsplash

By day, Fernando Falsetti was a newspaper salesman, but when he wasn’t at his stand, he was busy figuring out how to crack credit cards. Investigators found that he had been able to figure out the CVC of cards issued by a certain Argentinian bank by analyzing the card number and expiration date.

Security experts were astonished to discover a 30-page algorithm developed by Falsetti and written down in an old notebook. The patterns that he was able to identify and write down in his notebook made investigators suspect that Falsetti was no ordinary newspaper salesman, and indeed, he wasn’t. According to Clarin, he is a trained computer engineer specializing in systems and telecommunications who simply decided to change professions at some point. Still, even for a computer engineer, his algorithm is nothing short of impressive.

So how did this brilliant mind eventually get caught? Well, he may be a genius when it comes to figuring out complicated numerical patterns, but covering his tracks isn’t Falsetti’s strong suit. You see, after figuring out how to crack credit cards, he used them to buy satellite television subscriptions from his own newspaper stand, so he could earn a commission from them. It was a relatively small sum that he thought most people wouldn’t notice or report.

However, while people didn’t seem to notice the sums deducted from their credit cards, hundreds of them did notify the satellite television company that they had never bought the subscription and wanted to cancel it. Suspecting some sort of fraud, the company filed a complaint.

Falsetti had made no effort to cover his tracks. he simply used the card data to make purchases from his newspaper stand, and even kept all the invoices in his house for the investigators to find. All police had to do was check the IP from where the purchases were made and all the evidence was waiting for them.

For now, Falsetti has been set free, but the investigation is ongoing and he may have to do some jail time because of his brilliant mind. Argentinian media reports that the scale of his fraud is around a million pesos ($8,260).