Hal Pomeranz, Deer Run Associates In Part 3 of this series we looked at the EXT4 extent tree structure for dealing with very large or very fragmented files- basically any situation where you need more than the four extent structures available in the inode. Go back and read that part now if you haven't already, … Continue reading Understanding EXT4 (Part 4): Demolition Derby
Hal Pomeranz, Deer Run Associates Well I certainly didn't plan on three months elapsing between my last post on EXT4 and this follow-up, but time marches on. That was supposed to be a clever segue into the topic for this installment- the new timestamp format in the EXT4 inode. OK, I know what you all … Continue reading Understanding EXT4 (Part 2): Timestamps
Timeline analysis is a highly valuable tool. However, like everything else in computer forensics, it requires a skilled investigator to examine all the data available in order to find the evidence and provide an accurate account of the events. When analyzing Windows systems, it is common to use key timestamps in forensics such as Creation Date, Last Modified Date, Last Accessed Date, and the Last Modified Date for the file's Master File Table (MFT) entry. A key factor in using these timestamps is to not rely solely on a single timestamp, but use the combination of these timestamps in digital forensics. The combination of these timestamps can prove to be far more powerful and revealing than any single timestamp on its own. I will use an example to illustrate.
A forensic investigator was reviewing volatile evidence collected during an investigation into
Manipulating timestamps on Unix and Linux systems is as simple as touching a file on the file system. Of course, the individual attempting to modify timestamps will need to have permissions to do so on the file(s) in question.
On Windows based systems changing time stamps has historically required the use of third-party tools. However, Windows 7 and Windows Server 2008 will reportedly ship with Windows PowerShell installed.
Among the many advanced capabilities of Windows PowerShell is the ability to modify three different timestamps for Windows file systems. These are the file creation time, last access time and modification time. Forensic analysts should also be familiar with the metadata change time that is updated to reflect changes in