To achieve this, an attacker would require: a stolen card, two Android smartphones, a custom-made Android app that can tamper with a transaction’s fields. The app is installed on both smartphones, which will act as emulators. One smartphone will be placed near the stolen card and act as a PoS emulator, tricking the card into initiating a transaction and sharing its details, while the second smartphone will act as a card emulator and be used by a crook to feed modified transaction details to a real-life PoS terminal inside a store.
A team of scientists from a Swiss university has discovered a way to bypass PIN codes on contactless cards from Mastercard and Maestro. From a report: The now-patched vulnerability would have allowed cybercriminals to use stolen Mastercard and Maestro cards to pay for expensive products without needing to provide PINs on contactless payments. Discovered by a team from the Department of Computer Science at the ETH Zurich university, the attack is extremely stealthy and could be easily deployed in a real-world scenario if new bugs in contactless payment protocols are discovered. The general idea behind the attack is for an attacker to interpose itself between the stolen card and a vendor’s Point-of-Sale (PoS) terminal, in what security researchers would normally call a Man/Person/Meddler-in-the-Middle (MitM) scenario.