Comment by mike_hearn

You can use it and it's a good idea, although it's meant to stop exploits rather than deliberate backdoors.

The idea is that the library starts a separate thread to do any complex operation and then waits for it in the API call the user code made. The thread landlocks itself and then begins the operation. If something goes wrong the code is confined.

Of course in this case it doesn't work because the sandbox is controlled by the attacker, so they can just turn it off or make it weaker than it should be. But you can also do things other ways.