The overlay skimming devices pictured here include their own tiny magnetic read heads to snarf card data from the magnetic stripe when customers swipe their cards. Consequently, those tiny readers often interfere with the legitimate magnetic card reader on the underlying device, meaning compromised self-checkout lines may move a bit slower than others.
The app used the near field communication (NFC) antenna built into the Galaxy SIII phone, a feature available on many phones running Google’s Android operating system. The antenna is normally used to allow two phones to talk to each other.
He told SC last month that while the weaknesses in the cards was concerning, it was not an effective means to harvest lots of credit card numbers,
However it could be attractive for unskilled users for low-scale fraud.