An NFC relay attack is a type of cyberattack where criminals intercept and relay communication between a contactless device, like a smartphone or payment card, and a reader, such as a payment terminal. By using two devices - one near the victim’s device and another near the payment terminal - the attacker can trick the system into accepting unauthorized transactions, even if the victim’s device is not physically close to the terminal. This exploits the trust in near-field communication (NFC) technology, potentially allowing fraud without the victim’s knowledge.