MasterCard said its fraud monitoring system identified a series of fraudulent transactions in April.
MasterCard and CardSystems have offered differing explanations of how the data breach was uncovered. The data exported included names, card numbers and card security codes. The breach took place at the Tucson office of CardSystems Solutions, a company that processes transactions on behalf of merchants and financial institutions.Īs of Monday, MasterCard and CardSystems said that of the more than 40 million accounts exposed, information on only 68,000 Mastercard accounts, 100,000 Visa accounts and 30,000 accounts from other card brands are known to have been exported by the hackers. Of the cards involved, 13.9 million were MasterCard-branded cards, which include Maestro and Cirrus, and 22 million were Visa cards, said Visa spokeswoman Rhonda Bentz. "It looks like a hacker gained access to CardSystems' database and installed a script that acts like a virus, searching out certain types of card transaction data," said MasterCard spokeswoman Jessica Antle.
Over 40 million card accounts were exposed to potential fraud due to a security breach that occurred at a third-party processor of payment card transactions, MasterCard International said last Friday. CNN's Allan Chernoff reports on a security breach at a third-party payment processor that is impacting millions of credit card users.