Universal Plug and Play (UPnP) software
I've said from the BEGINNING that Autoplay, UPnP etc are inherently stupid. Making use too simple at price of security.
I've always disabled uPnP on routers and it and SSSD (sp?) on Windows Services, as well as all other silent automatic code running except USB.
USB HID is another issue. Maybe use USB cables carefully opened and the Data wires cut? Esp. when travelling, though sadly DC voltages/resistors on the D+ & D- in the charger tell the appliance what the maximum charging current is, so you might only get 500mA instead of 1A or 2A.