Save Mart Supermarkets issued a consumer advisory about card-reader breaches at 20 of its stores. Like pay-at-the-pump gas terminals and ATMs, self-service payment terminals are easy targets for fraudsters. Fraudsters typically compromise card readers and PIN pads via two methods. One method uses a physical overlay that skims card details while a nearby camera captures PINs as they’re entered on the pad. The other method requires the attacker to replace the PIN pad with one that’s been manipulated to record details.”]
Source: https://www.govinfosecurity.com/pci-effectively-preventing-fraud-a-4290