The Harvester is a built-in tool in Kali used to obtain information of user’s email, domain,  employee names, open ports and banners from different public sources like search engines.

This is usually used by penetration testers for foot printing.

To begin using the tool, just type :

theharvester -d companyname.domain -l 500 -b google

500 is the amount of results wanted. It can be replaced with any number

Google is the search engine, we can change it to

• twitter
• linkedin
• bing
• etc

It will then show results depending on which search engine you choose.