Security Headers
Analyze HTTP response headers and provide basic analysis of the target site’s security posture Security Headers
SSL Server Test
Analyzes a server’s SSL/TLS configuration and compares it against current best practices. SSL Server Test
Netcraft
Useful online passive reconnaissance tool to gather domain information. Netcraft
Github
It is possible to enumerate files/repos/code on github, such information could contain sensitive data about a webpage/domain such as source code and credentials.