The paging file and its importance in digital forensics

Operating systems have the ability to use a portion of the hard disk as an extension of RAM. This is referred to as virtual memory and is usually a good idea if a computer or laptop has limited RAM. Although the hard drive is much slower than the RAM, the swap or paging file on the disk can store files and programs that are being accessed less, leaving the RAM available to store data that is being frequently accessed. This process involves the operating system swapping pages of data that are less frequently used and moving data to the dedicated paging file area on the hard drive.

The paging file is very important to us in forensics investigations. Although not as volatile as RAM itself, due to being stored on the hard disk, it is a hidden file in Windows called pagefile.sys, and should always be inspected using tools of your choice as this file may reveal passwords for encrypted areas, information from sites visited, documents...