This attack will allow you to mine cryptocurrencies using all the end users' devices (laptops, smartphones, tablets) in a public wifi network.
It's being done by placing your device between the router and the devices and injecting a piece of Javascript in every webpage that the end users visit. This way some CPU power will be taken and used for the mining of crypto valuta. The initial rerouting is made by finding the end users' MAC address, using the ARP spoofing principle.
The idea was called The Coffeeminer, after a similar but different attempt to hijack all devices in a public wifi network at Starbucks Buenos Aires.
The proof-of-concept was designed by the developer Arnau Code, who tried to impose this in a real life example and had positive results. If you're interested in the code and how to set this up, check out his webpage at https://arnaucode.com/blog/coffeeminer-hacking-wifi-cryptocurrency-miner.html.