Since lsusb is saying that /dev/bus/usb/001/007 0 is the flash drive than I would say maybe it's a configuration issue
Maybe another member will know more about configuration issue's. Sorry I don't know how to tell--
If something on the flash drive is trying to run it may be that it is not functioning because your machine is not set to boot to usb first. Unless that is not what you want.
Is the flash drive formatted with grub and a distribution on it?
This was the only article I could find on usbtest.c.
These links might help too-
If that doesn't help you could try opening the terminal and try running:
The console should show you the path to the file.
Also you can try looking in lsmod
where the modules and drivers are listed.
The usbtest.c might be in the Ubuntu Package Search-
Look in Synaptic Package Manager too it might be in there.