[fghtr]

Another reason to use QubesOS, where usb devices are connected to a separate virtual machine without any networking. And any usb keyboards are only activated after a confirmation.

[diegoperini]

Noob question: How do you confirm?

[fghtr]

Qubes is designed for laptops, so your first keyboard does not need any confirmation (it's not connected via usb).

upd: Alternatively, for installations with a usb keyboard, this defence is disabled.