> 2. Modify LoginWithBackdoor.cpp to also accept the password “backdoor” by doing a find-and-replace that modifies the if-condition checking the password

Yeah, how is this going to generalise to _any_ program that gets compiled without introducing bugs in the executable? If you can write a backdoor that can accept _any_ program and compormise its integrity you can solve the haulting problem, can't you?

So this only works if the bad compiler has access to the source code that its compiling before hand and a _hand crafted_ hack is made for it. With opensource projects like the Linux kernal i can see this is a problem but for everyone else, meh.