Friday, February 12, 2016

Forensic Friday: Get-ForensicUsnJrnl

[This article is a continuation of my Forensic Friday series.  Every Friday I will provide a short post on a forensic topic of interest or PowerForensics functionality (such as cmdlet descriptions, use cases, and details about lesser known features). Subscribe to Invoke-IR so you don’t miss a Forensic Friday!]

Welcome back to Forensic Friday! This week I want to highlight the Get-ForensicUsnJrnl cmdlet, which parses the $UsnJrnl file or NTFS change journal.The UsnJrnl is responsible for keeping track of file system operations such as file creation, deletion, and truncation. During an investigation I highly recommend inspecting the $UsnJrnl as it provides extremely detailed context about what has transpired on the file system. For example, this is especially helpful in providing details about a deleted and otherwise unrecoverable file.

Common Use

By default, this cmdlet parses the $UsnJrnl file (\$Extend\$UsnJrnl) on the system’s C: volume, but can be pointed at any logical volume. An exported $UsnJrnl file can be parsed using the -Path parameter in order to perform offline analysis. I’ve listed a few examples below. The -Usn parameter tells Get-ForensicUsnJrnl to parse and return a single entry.

Parse a volume’s UsnJrnl & store in $usn variable (Example using volume “C:”):
$usn = Get-ForensicUsnJrnl -VolumeName C:

Parse $UsnJrnl file based on path & store in $usn variable (Example path C:\$Extend\$UsnJrnl):
$usn = Get-ForensicUsnJrnl -Path ‘C:\$Extend\$UsnJrnl’

Parse $UsnJrnl entry based on Update Sequence Number (Example with Usn #1189553536):
Get-ForensicUsnJrnl -VolumeName C: -Usn 1189553536

- Invoke-IR - By Jared Atkinson -