According to information, the payment cards of 455,000 Turkish citizens are online for sale.
Researchers from the company Group-IB reported that payment cards were found exposed on Joker's Stash, the largest online card store.
The card details were published in four "batches" between October 28 and November 27. This is the largest theft and sale of Turkish payment cards in recent years.
“Cards from Turkey are very rare in such stores,” Group-IB said. “In the last 12 months, it is the only major sale of payment cards related to Turkish banks.
Group-IB, which has been tracking the case since October, estimated that selling all the cards would bring the hackers more than $500,000 in profits.
According to researchers, the exposed cards are both debit and credit cards and come from various banks in Turkey.
The wide variety in card types and different banks prove that the data was stolen in a different way and not by a breach of a bank's system.
“All credit and debit cards found in this database contained the following information: expiration date, CVV/CVC, cardholder name as well as some additional information such as email, name and phone number,” said a senior Group IB executive.
The fact that information, such as emails and phone numbers, is available means that card details were not stolen by skimming devices installed in ATMs or PoS devices.
The company believes there are three possible sources: (1) phishing sites where users have entered their personal and financial information, (2) malware that stole data from victims' browsers, or (3) JavaScript-based skimmers that stole data from an online store where users had entered their information.
Researchers believe the third option is the most likely.
“The source of this leak remains unknown”, said the company.
Group-IB informed the Turkish authorities to investigate the case and take appropriate measures.
This incident is the second largest payment card sale that Group-IB has uncovered this year. In October, the company discovered that 1.3 million Indian card details were also for sale on Joker's Stash.
