USB devices phoning home

USB is a versatile standard defining various features to allow maximum flexibility for evices. This flexibility, by design, leads to complex device configurations, combining multiple functions into one, making it impossible for users to identify the function of a device by its looks. This can be exploited by crafting programmable USB devices, looking and behaving like an ordinary flash drive that also expose virtual network devices and other functionality to their host OS. This paper outlines such a device, exploiting several USB features to establish a rogue HTTP channel used to leak data stored on the device’s disk to an internet back end. We describe the device itself and its architecture and our conclusions and methods for dealing with the issues presented in a user–friendly way