Every organisation has an online footprint consisting of the IPs, domains, servers, services and applications they present to the Internet. Often hackers are successful because they're better at finding the parts of the footprint the defenders didn't know about. So, to be a successful hacker or defender, you need to be able to able to generate a comprehensive footprint. SensePost has been doing footprinting for years and has finally distilled this knowledge into a robust and flexible network reconnaissance tool - Yeti. During this talk, a brand new Yeti will be released (for free) and the finer aspects of network footprinting will be discussed including many of the less common tips and tricks we use to be successful.