Windows Registry and its Forensic significance - Part 3

The Windows Registry serves as the heartbeat of a Windows operating system, housing a hierarchical database of configuration settings, preferences, and critical information about hardware, software, and user profiles. For forensic experts, it represents a goldmine of data that can unveil a user's digital history.

Hives: Compartments of Secrets

To grasp the forensic significance of Windows Registries, we must first delve into their hive structure. These hives act as compartments, each storing specific categories of data. Here are key hives with their file paths:

HKEY_LOCAL_MACHINE (HKLM)

Stores system-wide settings and software information. Its file path is C:\Windows\System32\config\SOFTWARE.

HKEY_CURRENT_USER (HKCU)

Contains user-specific settings and application data. Its file path varies by user but is typically found at C:\Users\[Username]\NTUSER.DAT.

HKEY_USERS (HKU)

Houses user profiles, with each profile having its own subkeys and settings. File paths follow a similar structure to HKCU.

HKEY_CLASSES_ROOT (HKCR)

Maps file extensions to applications. Its file path is C:\Windows\System32\config\SOFTWARE

Keys associated with forensic investigation that can unveil traces of digital crime some of them are discussed as below -

Software Installation Timestamps

In HKLM, navigate to SOFTWARE\Microsoft\Windows\CurrentVersion\Uninstall. Examine the "InstallDate" value to determine when software was installed.

User Profile Path

In HKCU, check the ProfileImagePath value under SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\Shell Folders to find the user's profile path.

Last Shutdown Time

In HKLM, look at SYSTEM\ControlSet001\Control\Windows. The "ShutdownTime" value reveals when the system was last shut down.

User Login History

Examine SOFTWARE\Microsoft\Windows\CurrentVersion\Authentication\LogonUI under HKLM to find user login history.

User Account Password Hashes

For security-related analysis, look in HKLM at SAM\SAM\Domains\Account\Users. This contains password hashes, but beware of encryption.

Program Execution Logs

Inspect HKCU under SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\User Assist to find information about executed programs.

We will cover some of the popular tools that are used to investigate such evidence with an example.

Registry Repper is a useful tool for Windows Registry analysis. It allows you to extract, analyze, and edit Registry data efficiently. In this example, we will walk through the process of using Registry Repper for Registry analysis with a specific scenario.

Scenario: Investigating Recent Application Usage

1. Launch the Registry Repper application.

1. Go to "File" and select "Open Hive." In this example, we will analyze the user's Registry hive, which is typically located at C:\Users\[Username]\NTUSER.DAT.

1. Select the NTUSER.DAT file for the user you're investigating and click "Open."

1. Using the Registry Repper interface, navigate to the Registry key that contains information about recently used applications. In this case, the path is usually: SOFTWARE\Microsoft\Windows\CurrentVersion\Explorer\UserAssist.

Once you've reached the desired Registry key, Registry Repper will display the information contained within it. Look for entries related to recently used applications.

The data might appear in encoded or obfuscated formats, as it often does in the UserAssist key. Registry Repper can assist in decoding this data to reveal the names of the applications and their execution counts.

Analyze the decoded data to determine which applications have been recently used, along with the frequency of their usage. This information can provide valuable insights into the user's activities.

If needed, you can export the results for documentation or further analysis. Registry Repper typically allows you to export data in various formats, such as CSV or text files.

Ensure that you document your findings thoroughly, including timestamps and any other relevant details. This documentation is crucial for maintaining the integrity of your forensic analysis.

RegRipper is another popular tool for Windows Registry analysis. Let's use it to extract information about user accounts.

Scenario: Extracting User Account Information

1. Download and install RegRipper from its official repository.
2. Launch the RegRipper command-line interface.
3. Use a RegRipper plugin like "userassist" to extract data related to user account activity. For example:

rip.exe -r <Path_to_NTUSER.DAT> -p userassist

RegRipper will process the Registry hive and extract information about recently used applications and user account activity.

Review the generated report to gather insights into user account usage patterns.

Using Windows Registry Editor (Regedit)

While not a dedicated forensic tool, Windows Registry Editor (Regedit) can be used for basic Registry analysis.

Scenario: Examining Recent Documents

Open the Windows Registry Editor by pressing Win + R, typing "regedit," and pressing Enter.

Navigate to the Registry key that contains recent document information: HKEY_CURRENT_USER\Software\Microsoft\Windows\CurrentVersion\Explorer\RecentDocs.

In the right pane, you'll see a list of file shortcuts. These represent recently accessed documents.

Examine the document shortcuts to identify recent files and their paths.

Conclusion:

Windows Registries house the digital breadcrumbs we leave behind in the world of technology. Their forensic importance, particularly concerning software, user data, and password access, is undeniable. As digital forensic professionals, mastering the art of navigating Windows Registries is a skill of immeasurable value. In the ever-evolving landscape of cybersecurity and digital forensics, understanding the Windows Registry remains indispensable.