The attackers have modified the withdrawal limits on prepaid cards
Around Christmas time, a cybercriminal group managed to steal $11 million (8.3 million EUR) in a couple of cleverly planned ATM heists. As a result of the incident, Visa released an alert to all card issuers.Brian Krebs reports that the first attack took place on Christmas Eve. The crooks used prepaid debit cards associated with accounts they owned to withdraw $9 million (7 million EUR) from ATMs located in several countries from around the world.
The second attack took place just before New Year’s Eve. This time, a card network from India was targeted and around $2 million (1.5 million EUR) were stolen.
Normally, prepaid card holders aren’t allowed to withdraw too much money over a short period of time. However, according to Visa, the hackers gained access to the authorization systems and card parameter information and manipulated the daily withdrawal amount limits.
The cybercriminals leveraged web-based security and planted backdoors to maintain access.
For the time being, it’s uncertain what organizations have been hacked or what issuers' prepaid cards have been misused.