Types of Tools

When it comes to digital forensic investigations, having the right set of tools is crucial for investigators to obtain the necessary information. There are various types of tools available, and it’s up to the investigator to determine the appropriate one based on the case. Digital forensic tools can be divided into these three categories.

1. Open Source Tools

Open Source tools refer to software programs that are developed and maintained by a community of users and are freely available to use. It means that the source code is publicly available, and anyone can view, use or modify it, allowing collaborative development from various contributors. Popular open-source digital forensic tools include:

  • Autopsy: This tool is used for analyzing computers and smartphones. It allows investigators to recover deleted files, analyze internet history, and extract data from various applications.
  • The Sleuth Kit: This tool is a library of tools for analyzing disk images and file systems. It provides investigators with a more in-depth analysis of the file system and deleted files.

2. Proprietary Tools

They refer to software programs that require a license for use and are developed and maintained by a particular organization. Proprietary tools are generally expensive but are also often more powerful and user-friendly than open-source alternatives. Some popular proprietary tools include:

  • EnCase: This tool is widely used in digital forensic investigations by law enforcement agencies. It can examine various types of devices and file systems, collect evidence, and analyze complex metadata.
  • FTK (Forensic ToolKit): Used to collect, process, and analyze digital media, including computers, mobile devices, and cloud storage.

3. Self-created Tools

These tools refer to any tool that is developed and created by an investigator for a specific case or research project. They are not commercially available and are usually tailored to a specific situation or need. For example, an investigator may create a tool to extract data from a particular application or to detect malware on a particular computer network.

Takeaway: The proper selection of tools in digital forensic investigations is critical in the search for evidence. Whether it’s an open-source tool for general purposes, a proprietary tool for complex metadata analysis, or a self-created tool for a specific situation, it is essential to select the appropriate toolset for identifying and analyzing information.

Digital Forensics Process

The process involves several steps that enable forensic investigators to investigate technical incidents and extract relevant evidence. Here, we will discuss the four main phases along with their sub-parts in the digital forensics process.

Main Phases

1. Seizure

The first phase of the digital forensics process is a seizure, where the suspect device is seized and properly packaged before being transported to a digital forensics lab. The investigator should have a court-issued search warrant and the appropriate permission to confiscate the suspect device. Devices subject to seizure can be any type of computing device such as a desktop computer, server, laptop, tablet, smartphone, external hard drive, USB stick, or IoT device.

If the suspect device is still running upon arriving at the crime scene, the investigator should acquire volatile memory if possible. Volatile memory may contain critical information for the investigation like passwords, chat logs, running programs, etc.

In some cases, jurisdictional challenges may arise that prevent forensic investigators from seizing a device. For example, if the suspect digital device is located in another country, how can it be seized? An international search warrant takes a lot of time and effort and is not applicable in all cases.

2. Evidence Acquisition

Here, a professional computer forensic technician creates a bit-by-bit or complete forensic image of the device’s hard drive and RAM, if applicable. Multiple forensic images are preferred to ensure the integrity of evidence and the examination will be conducted on these copies in the lab.

3. Evidence Analysis

The third phase of the process is evidence analysis. Here, a forensic image is analyzed using different court-approved tools and techniques to derive useful leads. These tools include EnCase, Sleuth Kit, Volatility, and AccessData. The forensic examiner employs these tools for tasks such as recovering deleted files and emails, detecting hidden data, and retrieving web browser history and chat logs.

4. Evidence Presentation

The final phase of the digital forensics process is evidence presentation, where a comprehensive report detailing the findings is produced. Essentially, the language used in the report is understandable to non-technical people like judges, attorneys, and juries.

Sub-parts of the Process

1. Identification

This is the first step of the process in which investigators identify the purpose of the investigation, potential digital evidence, and how it’s stored.

2. Preservation

This step involves securing the evidence by isolating and safeguarding it, preventing tampering, and ensuring that it remains untainted.

3. Collection

The evidence is collected using approved processes and techniques and packed in a Faraday bag to prevent further harm to it.

4. Examination

An examination is a precursor to accessing the evidence’s integrity and any details it may contain.

5. Analysis

In this step, the investigator joins the dots by retrieving data and constructing bits of evidence that may have been deleted.

6. Interpretation

The interpretation stage involves an investigator reviewing and analyzing the examination results and concluding the findings.

7. Documentation

The documentation stage involves maintaining thorough records of the process and its findings, preparing reports, including documenting the crime scene along with photographing, sketching, and mapping.

8. Presentation

The presentation stage is necessary when cross-examination is necessary. It should be in simple terms to help commoners understand the investigation’s results.