2005 — Cardsystems Solutions: Third-party payment processor for Visa, Mastercard,…
Technical writeup
Third-party payment processor for Visa, Mastercard, Amex, and Discover. CardSystems was fingered by MasterCard after it spotted fraud on credit card accounts and found a common thread, tracing it back to CardSystems. An unauthorized entity put a specific code into CardSystems' network, enabling the person or group to gain access to the data. It's not clear how many of the 40 million accounts were actually stolen.
Root cause
Hacked