Knark is a kernel-based rootkit for Linux 2.2. Hides files in the filesystem, strings from /proc/net for netstat, processes, and program execution redirects.
You can download it from the following link: https://packetstormsecurity.com/files/download/11473/knark-0.50.tar.gz
Source: https://packetstormsecurity.com/files/11473/knark-0.50.tar.gz.html