How is WFD used?

Question

Could someone use WFD to transfer files from my device without my knowledge of the transfers or the use of the WFD service?

Answer 1

Theoretically, yes, someone could hack your phone since there is also a current issue with the WiFi on mobile devices. An attacker can gain access to your phone using advanced tools. You wouldn't even know it's connected to your device, but that chance to happen is close to 0,001 %.

You should update the firmware of your phone, also stay away from public networks. There is also an article about this issue.