There's always Ken Thompson's hack of the compiler to insert a backdoor into the login program on Unix. See Reflections on Trusting Trust: https://www.win.tue.n

There's always Ken Thompson's hack of the compiler to insert a backdoor into the login program on Unix. See Reflections on Trusting Trust: https://www.win.tue.nl/~aeb/linux/hh/thompson/trust.html https://www.win.tue.nl/~aeb/linux/hh/thompson/trust.html .