This is a breve tutorial about useful tools for the first phase of the ethical hacking, gathering information. I will explain the following tools:

• Whois
• DNS Enum
• theHarvester
• whatWeb

I hope you understand that my goal is not to make a complete guide to understand the tools. Since I think that if I explain everything to you, you will probably not investigate. On the other hand, I would certainly have to write a manual.