Beginners guide to hacking and penetration testing (2017)
Maltego:
Maltego is a software tool (free community edition and paid pro version) that is used for open-source intelligence gathering. Maltego can easily uncover vast amounts of information easily searching for machines, people, email addresses, Twitter accounts, etc. Maltego can be downloaded on Paterva's website at: https://www.paterva.com/web7/
When Maltego is launched you will be presented with several basic templates for scanning (Wikipedia
Edits, Company Stalker, Level 1-3 footprinting, Personal Email Addresses, etc). To start select a scan.
In our case we are going to do a quick Level 1 scan of Microsoft.com so We select Footprint L1 and enter in the address, this case www.microsoft.com
After a few moments we are already seeing results of our scan coming in. We can see the DNS names, Website(s), IP addresses, etc. If we right click any of these entities we can drill down for further information.
Spending time understanding Maltego and how it works will help be one of your "go to" tools for Open Source Intelligence Gathering.