The security piece of this does not amuse me. You'll have to yank the freakin' plug out of the wall to get a hacked one of these offline.
I was wondering the same thing: what does this pose as far as security goes?
Lets assume that what they say about a "production model" is accurate.
# When a host PC is powered up, the Somniloquy does nothing and is transparent to the host OS. In a production version, the Somniloquy's processor would be powered down in this mode, though the researchers say they were unable to implement power-down on the prototypes.
# When the host PC initiates sleep, the Somniloquy detects this and transfers network state to the secondary processor, including ARP table entries, IP address, DHCP lease details, and wireless SSID, thereafter becoming capable of "impersonating" the host.
Note how the on board OS and CPU are powered down when the Host computer is powered up. You would need to first violate its own security and upload a ARM compatible piece of malware to take control and download a x86 piece of malware. The x86 malware would then need to be accessed by the host system while the Somniloquy OS and network connection are inert (or change the firmware to make it stay active) and be capable of taking over that host system.
It seems to me that there would be too many stages to go through and most malware authors would take the simpler step of attacking the x86 machine directly not through a proxy.
Put the minimum amount of software on the system and lock each piece down to the lowest level of access it can have to still do its job. Build it into a router and have the router treat the SD card as a remote HD - accesible both by the download function and other computers. The router could have two different CPUs each with its own OS and memory, one controlling the router functions and the other the torrent (which could be turned off to conserve power when unused). They would need to control 1st the torrent then the router to finally be able to attack your system which would be using both a different processor architecture and a different OS. You could control the torrent software by reading and writing to a config file on the SD card that the torrent checks on a cycle. The router could even be set to force a restore to default if the torrent software tries to access anything but the torrent allowed resources (killing any torrent in process and ideally any malware).