Bangalore: Giant card-payment processors namely Visa, MasterCard, AmEx (American Express) and Discover Financial Services were hit by a data-security breach. A third-party service provider, Global Payments, an Atlanta based company, discovered that its systems were compromised by unauthorized access.

In this credit card heist, more than 1.5 million MasterCard and Visa accounts are believed to be hacked. As per logical terms, the Consumers aren't accountable for unauthorized purchases made on their cards.

WSJ report suggests that the breach took place between January 21 to February 25, 2012. MasterCard reported that it is investigating the breach, but its core network is not hacked.

“MasterCard is currently investigating a potential account data compromise event of a U.S.-based entity. As a result, we have alerted payment card issuers regarding certain MasterCard accounts that are potentially at risk. It is important to note that MasterCard’s own systems have not been compromised in any manner. MasterCard is concerned whenever there is any possibility that cardholders could be inconvenienced and we continue to both monitor this event and take steps to safeguard account information”, MasterCard said in a statement, as quoted by Mashable.com.