A group of security researchers discovered a new method dubbed Distributed Guessing Attack to hack VISA credit card in just 6 seconds. The method is likely to have been used in the recent cyber attack against the Tesco bank that resulted in the theft of 2.5m. The attackers can gather the card information one field at a time making impossible for merchants to detect the fraudulent activity. The attack exploits two weaknesses that on their own are not too severe but when used together, present a serious risk to the whole payment system.”]
Source: https://securityaffairs.co/wordpress/54036/hacking/distributed-guessing-attack.html