Attacks targeting connected cars have already been presented in several conferences, as well as different tools to spy on CAN buses. However, there have been only a few attempts to create something similar to a useful backdoor for the CAN bus. Moreover, some of those proofs of concept were built upon Bluetooth technology, limiting the attack range and therefore tampering its effects. Those things are old! Throughout our research we have successfully developed a hardware backdoor for the CAN bus, called "The Bicho". Its powerful capabilities render it a very smart backdoor. Have you ever imagined the possibility of your car being automatically attacked based on its GPS coordinates, its current speed or any other set of parameters? The Bicho makes it all possible. All the "magic" is in the assembler-coded firmware we developed for a PIC18F2480 microcontroller. Aditionally our hardware backdoor has an intuitive graphical interface, called "Car Backdoor Maker", which is open-sourced and allows payload customization. The Bicho supports multiple attack payloads and it can be used against any vehicle that supports CAN, without limitations regarding manufacturer or model. Each one of the payloads is associated to a command that can be delivered via SMS, allowing remote execution from any geographical point. Furthermore, as an advanced feature, the attack payload can be configured to be automatically executed once the victim's vehicle is proximate to a given GPS location. The execution can also be triggered by detecting the transmission of a particular CAN frame, which can be associated with the speed of the vehicle, its fuel level, and some other factors, providing the means to design highly sophisticated attacks and execute them remotely.