Forensic Investigation: Pagefile.sys

In this article, we will learn how to perform a forensic investigation on a Page File. There is a lot of information that can be extracted from valuable artifacts through a memory dump. Yet, there is more: you can perform memory forensics even without a memory dump that is by virtual memory analysis.

There are records on the drive that contain a few pieces of memory. These files are pagefile.sys, swapfile.sys, and hiberfil.sys. We will be moving forward with pagefile.sys.

Table of Contents

  • Introduction
  • Capturing the memory and pagefile using FTK imager
  • Analyzing using Belkasoft Evidence Centre

Introduction

The Pagefile.sys also referred to as a swap file or virtual memory file is utilized inside Windows operating frameworks to store information from the RAM when it turns out to be full. The pagefile.sys in Windows operating framework is located at C:\pagefile.sys. Windows OS supports up to 16 paging files; only one is used currently.

At whatever point you open an application in Windows, your PC will consume RAM. At the point when you have more applications open than the RAM on your PC can deal with, programs previously running in the RAM are moved to the Page file. This is known as Paging and implies the Page file goes about as reinforcement RAM, also known as virtual memory.

Capturing the memory and pagefile using FTK Imager

We will use FTK Imager to capture the memory along with the pagefile.sys.

FTK® Imager is a tool for imaging and data preview FTK Imager also create perfect copies (forensic images) of computer data without making changes to the original evidence. You can download FTK imager from here.

Click on capture memory to create a memory dump.

 

The next step is to browse the destination path as you like, select the alternative “include pagefile” and click on Capture Memory.

The memory capture process will begin once you click on capture memory.

After completion of the process, the memory dump and page file will be carved in the destination folder previously selected.

Analyzing using Belkasoft Evidence Centre

Now to analyze the carved file we will be using the tool, Belkasoft Evidence Centre for analysis of the pagefile.sys. Belkasoft Evidence Centre is an all-in-one forensic tool for acquiring analyzing and carving digital evidence. You can download the free trial of the tool from here.

 First of all, let’s create a new case. Fill in the case information, select the root folder, if you want, you can add a case described as well. Click on create and open to proceed further with the analysis. 

To analyze the captured memory (pagefile), select the option RAM Image; add the pagefile.sys file you carved previously as the evidence source using FTK imager.

Choose the desired data type you would like to search for. There are a whole lot of data types supported by the tool. Click finish afterward.

Here is the dashboard for the case after completion of the above steps. It shows proper segregated information about the data carved from the pagefile. A total of 1097 files have been carved, which includes URLs, pictures, and other artifacts.

The case explorer tab right next to the dashboard tab allows expanding and viewing each profile column. The data has been carved from browsers, pictures, system files, and other files as well.

Let’s expand and analyze the Browsers profile. It has carved the chrome history which consists of URLs, let’s check the chrome carved section for more details. It consists of the URLs for the sites visited, one of which is highlighted in the following screenshot.

Another in browsers profile is opera. Analyze the opera(carved) profile similarly, shows details about the URLs visited.

The carved data from pagefile also consists of some images. These images can be from the sites I have visited and other thumbnails.

The great feature of the belkasoft evidence center is it allows you to simply right on the picture and analyzes it for various aspects such as check skin, detect pornographic content from the picture, detect text, and also faces. All these aspects are useful during live analysis.

Some system files are also carved from the captured virtual memory, show the NetBIOS name, file path, and size.

The timeline tab shows the overall view of the data carved for easy analysis along with the time and URL of the search site visited.

A search results tab is also there in the tool which shows predefined search results. The following screenshot shows the search engine results along with the link and profile name. 

Similarly, you can perform the forensic investigation for hiberfil. Export the hiberfil.sys (stores the data while the windows system is on Hibernate mode) using FTK located at C:/hiberfile.sys and further analyze it using Belkasoft Evidence Centre.

The analysis of virtual memory files serves a great purpose for web browser forensic.

Author: Vishva Vaghela is a Digital Forensics enthusiast and enjoys technical content writing. You can reach her on Here

Forensic Investigation: Disk Drive Signature

In this article, we will be using Disk Drive Signature to identify any suspicious changes in systems’ directories or files. Creating such signatures can help us protect our data in various ways.

Table of Contents

  • Introduction
  • Creating disk signature
  • Comparing disk signature

Introduction

A disk drive signature is created to identify the suspicious changes in your systems’ directories or files. This data incorporates information about a document’s path, size, and other file attributes.

To create a disk drive signature, we will be using the OS Forensics tool by PassMark Software. OS forensic allows you to create, compare, and analyse a disk drive signature.

Let’s first check what all files are present there on the Desktop as we are going to create a disk signature on desktop only to get quick results. You can create a Disk drive Signature of any disk or folder present on your system as per your requirement.

We are going to create a signature for my desktop only. To begin with let’s first check the files present on the desktop so that you can get a clear idea after comparison of disk drive signatures.

Creating Disk Drive Signature

To create a Disk signature, download the OS Forensics tool if you haven’t already. You can download it from here. You can create the disk signature by selecting the options highlighted in the following screenshot.

Select the desired directory to create the signature. Here, I have selected Desktop, browse the directory, and click start. So, the signature for the data drive will be created.

It will ask for the File Name, enter the File Name and click on Save. Now the signature for the selected drive will be created. Select a file name for your signature as per your convenience I will be naming the first signature “old signature” and the other one “new signature”, just to be clear while comparing both the signatures.

Now you can perform some modifications in the data drive like deleting or editing some files anything that you want. You can also repeat the same steps to create another signature after making all the alterations in the information drive.

After creating the before and after signatures, select compare signature as highlighted in the following screenshot. Browse the old and new signature in the respective column and select compare. The comparison of the disk signature helps to find any changes in the drive.

 The result will show the files with their difference status, whether the file is deleted, modified, or created along with the date and time. The result of after comparison of both the disk drive signature shows a total of 7 differences; 4 new files, 2 deleted, and 1 modified file.

From the bottom right, as depicted in the picture, you can separately view the files of difference as you like. For instance, if you want to view all the deleted files altogether select deleted files from the drop-down column.

Creating and comparing the disk drive signatures helps to know suspicious changes in your system as it creates a snapshot of the directory structure of the drive at the point of creation

Author: Vishva Vaghela is a Digital Forensics enthusiast and enjoys technical content writing. You can reach her on Here

Forensic Investigation : Prefetch File

In this article, we are going to study an important artifact of Windows, i.e. prefetch files. Every time you do anything on your Windows system, a file is created. These files are called Prefetch files. Through this article, we will learn how these are important and why do we need them.

Table of Content

  • Introduction
  • Forensic Analysis of Prefetch Files
    • WinPrefetch View
    • OS Forensic
    • PECmd
    • FTK Imager

Introduction

A Prefetch file is a file created when you open an application on your windows system. Windows makes a prefetch record when an application is run from a specific area for the absolute first time.

Prefetch files were introduced in Windows XP. Prefetch files are intended to accelerate the Windows boot process and applications’ start-up process. In Windows XP, Vista, and 7 the number of prefetch files is limited to 128 whereas in Windows 8 and above it is up to 1024.

Proof of program execution can be a significant asset for a forensic investigator, they can prove that a certain executable was executed on the system to cover up the tracks. Before initiating the forensic analysis of the prefetch record as a forensic examiner you should check whether the prefetching process is enabled.

To check the status of prefetching, open the following location in Registry editor:

The value is set as 3 by default as shown in the image above. The following values can be changed according to your prefetching needs. All the options that windows provide us with in order to customize prefetching are explained below:

  • 0:Prefetching Disabled
  • 1:Application Prefetching Enabled
  • 2: Boot Prefetching Enabled
  • 3:Application and Boot both Enabled

The metadata that can be found in a single prefetch file is as following:

  • Executable’s name
  • Eight character hash of the executable path.
  • The path of the executable file
  • Creation, modified, and accessed timestamp of executable
  • Run count (Number of time the application has been executed)
  • Last run time
  • The timestamp for the last 8 run time (1 last run time and other 7 other last run times)
  • Volume information
  • File Referenced by the executable
  • Directories referenced by the executable

The prefetch files are saved under %SystemRoot%\Prefetch (C:\Windows\Prefetch).

You can open the prefetch files location you can directly search for “prefetch “in the run command.

It can also be opened as a directory from the command prompt, which is a good news for all the command-line lovers.

Forensic Analysis of Prefetch Files

WinPrefetch View

WinPrefetch View is a tool to read and examine the prefetch files stored in your system. The tool was developed by Nirsoft. This utility deals with any variant of Windows, beginning from Windows XP to Windows 10.

You can download the tool from here.

You can easily open the details of a particular prefetch file by simply clicking on it. Here, I have opened HFS.EXE-D3CAF0BF.pf for a detailed view. It shows details such as created time, modified time, file size, the path of process run count, last run time, missing process.

OS Forensics

OS Forensic is a digital forensic tool, a complete package for forensic investigation by Passmark software. It is used to extract, analyze data, search files, recover deleted passwords, and recover deleted evidence, much more.

Download the tool from here.

Prefetch Explorer Command Line (PECmd)

PECmd is a command-line tool by Eric Zimmerman, used for bulk analysis of prefetch files.This tool can also export your prefetch artifacts to .csv and .css.

You can download the tool from here.

To begin with run the executable file. Let’s parse the prefetch file using this tool we will use the –d parameter to parse all the prefetch file.

In the image below, you can see the prefetch file for firefox.exe.The tool has parsed all the metadata as it has been explained in the introduction.

Similarly, through the following image, you can observe the prefetch file for HFS.exe. Such files will be created for every application you access.

FTK Imager

As a Forensic Investigator, you can always access the prefetch files to understand the case given to you. Because through these files, it can be determined that what was frequently used on the system that you are investigating. This can be easily done with FTK Imager. FTK imager allows one to view and analyze the prefetch file present in the drive. To access the prefetch file through FTK, just open the said tool and look for the Prefetch folder in the left panel as highlighted in the image below:

This is all on prefetch files. Now that we understand these files properly, we can customize it, access it, and use it as we need. The most important thing to know about prefetch files is that it a boon when comes to retracing a malware as any .exe file that has been run on the system, will be logged in prefetch files. Therefore, if a malicious file is executed; you can track it through this.

Author: Vishva Vaghela is a Digital Forensics enthusiast and enjoys technical content writing. You can reach her on Here