As a white-hat hacker for a big audit firm I spent days and nights in our “lab
The most interesting stage of a targeted attack is the reconnaissance, or footprint analysis. Here you use the web, search engines, whois, and nslookup, to discover as much about the target as possible. A whois lookup can tell you email address formats for instance (first letter last name @ company.com).

The link for this article located at www.zdnet.com is no longer available.