Hands on Hacking

Chapter 4Open Source Intelligence Gathering

A malicious hacker who is intent on gaining access to an organization's computer network in some way will almost certainly do their homework first; that is, gathering information on that organization and its computer systems. They will research individuals who work for, or are associated with, that organization and compile lists of domain names, hostnames, IP addresses, URLs, email addresses, and potential passwords, all without sending a single packet of data to any device associated with their target.

Think of a malicious hacker as a dedicated, hardworking, and meticulous individual (or a group of such individuals) and purge your mind of any other images associated with the word hacker.

The intelligence gathering process, whether performed by us or them, makes use of freely available, public information accessible to anyone who wants it and knows where to look. It is not protected in any way, and it does not cost anything to obtain. For that reason, it can be called open source. As a penetration tester or ethical hacker, you must at least be as diligent as a malicious hacker and carry out your research thoroughly, building up a picture of your target—your client's company and network—before you actually start doing any active hacking. A malicious hacker may not even visit their target's website, but you will almost certainly do this at the beginning of your engagement. Companies often want an open source intelligence (OSINT) assessment ...