Nikto is an Open Source web server scanner which performs comprehensive tests against web servers for multiple items, including over 3500 potentially dangerous files/CGIs, versions on over 900 servers, and version specific problems on over 250 servers.
You can download it from the following link: https://packetstormsecurity.com/files/download/148209/nikto-2.1.6.tar.gz
Source: https://packetstormsecurity.com/files/148209/Nikto-Web-Scanner-2.1.6.html