unknown computer connected to my modem

[happytelus]

After logging into my new Telus Actiontec modem, my Home Network shows all my devices connected including a device called, "unknown" wired computer, 192.168.1.68 After disconnecting all lan connectors from the back of the modem, the home screen for the modem still shows this device connected. What is this device? Should I dissemble it? How do I do this? 

[NFtoBC]

The Actiontec retains some connection info for a period. Can you reset the device and see what happens?
Also, I wonder if this is the modem itself assigning an IP address for its own use.