Erik Trulsson wrote:
Ken Thompson (one of the original creators of Unix) *did* put such a hack into their C compiler which would automatically add backdoor code when it compiled the 'login' program. This was many years ago and AFAIK the hacked Unix version was never released into the wild.
Are you sure your information is accurate. Neither of the references that you cite back you up on this. Yes, of course we all know of Ken's proposed design for this (from his ACM talk), but I never read anywhere before that this was actually carried out in the wild or otherwise.
