The Wayback Machine

At this point, the internet has been around for quite some time, and there are a number of retired web pages and websites. The Wayback Machine (https://archive.org/web/web.php) allows us to view previous versions of websites that may not even exist anymore. Think of it as the archive of the internet. Once we find the older version of our target site, we can scan for historical data that people didn't mean to expose. Now, before I got my start in security, I had no idea this tool was out there, but it's really interesting to use for fun as well (you know, like showing your kids what Amazon used to look like):

Figure 3.18 – The Wayback Machine home page

You can see here that they have saved over 456 billion web pages. The Wayback Machine goes through websites and detects any changes – if it detects a change, it makes a note and caches that information. As an example, I'll use my old company's website...