A tool that enables a hacker or penetration tester to capture RFID card data from up to three feet away will be released next week at Black Hat. The tool would allow an attacker or pen-tester to store the device inside a backpack and it would silently grab card data. An attacker can in theory capture card data, clone it onto a new card, and be able to access a physical facility. An attack has been tested numerous times with a 100 percent success rate; he added he s been able to train other consultants to use the tool.
Source: https://threatpost.com/long-range-rfid-hacking-tool-to-be-released-at-black-hat/101448/