Sneaky-sneaky is a bidirectional spoofed ICMP tunnel backdoor that has built-in encryption and logging capabilities. It communicates via echo replies keeping the true source IP address encrypted inside of the payload.
You can download it from the following link: https://packetstormsecurity.com/files/download/30637/sneaky-sneaky-1.48.tar.gz
Source: https://packetstormsecurity.com/files/30637/sneaky-sneaky-1.48.tar.gz.html