Cybercriminals add their own spying equipment to an automated teller machine or point-of-sale system (ATM) to copy the information they process from credit or debit cards. The typical targets include ATMs, PoS terminals, and gas stations, according to a report from Advanced Intelligence (AdvIntel) a fraud prevention company based in New York. The report was based on information from reputable shops and source intelligence. Smartphones and Bluetooth technology have also seen increased adoption among Russian skimmers.
Source: https://www.bleepingcomputer.com/news/security/carders-prefer-audio-skimmers-over-less-efficient-flash-skimmers/