A device for securing USB or Firewire port interconnections includes a microcontroller comprising a processor; a first connector/lead in communication with the microcontroller and configured to be coupled with a USB or Firewire external device; and a second connector/lead in communication with the microcontroller and configured to be coupled with a protected host. An optional user interface communicates with the microcontroller. When the microcontroller detects that the external device is coupled to the first connector/lead, the processor is configured to display a prompt on the user interface for a user to initiate inputs prior to the external device being allowed to connect with the protected host; or is configured to automatically prevent the external device from being connected with the protected host if the external device is on a blacklist of devices known to have device handlers in the protected host at a BIOS level, without modifying the protected host.