Just as we need to connect the dots to build a big picture, from a network forensics perspective, we need to correlate logs in order to get to the big picture of activity on a network. All devices that maintain logs of events are a great resource to track intruder activity. In our role as Network 007s, we will use these logs to try and track every step of the route taken by an intruder in our network.

Let's begin by trying to understand what logs are. A log, as the name suggests, is a record of information generated in response to a specific event or activity that occurs on a system or network. A log aims to capture the who, what, when, and where of an event. Logs can include the information about the date and time of the activity; device or application the log relates to; associated user or account; type of log—such as error, warning, information, and success or failure audits...