Processing of Cyber Crime Scene

Processing a cyber crime scene is a specialized and intricate process that requires a combination of technical expertise, adherence to legal protocols, and meticulous documentation. Unlike traditional crime scenes, a digital crime scene is often virtual, involving networks, servers, and electronic devices. The primary goal is to collect, preserve, and analyze digital evidence without altering or destroying it, ensuring it remains admissible in a court of law.

The Five Stages of Digital Forensics

The entire process of processing a cybercrime scene is a part of digital forensics and is generally broken down into five core phases:

Identification,
Preservation,
Analysis,
Documentation,
Presentation.

1. Identification

This is the first and most crucial step. It involves identifying all potential sources of digital evidence. This can include a wide range of devices and data storage locations:

Computers: Desktops, laptops, and servers.
Mobile Devices: Smartphones, tablets, and smartwatches.
Storage Media: Hard drives, solid-state drives (SSDs), USB flash drives, and memory cards.
Network Systems: Routers, firewalls, and network traffic logs.
Cloud Services: Data stored on cloud platforms like Google Drive, iCloud, or Dropbox.

A key part of this stage is also assessing the situation and determining if the system is "live" (powered on) or "dead" (powered off). The approach to evidence collection differs significantly based on this assessment.

2.Preservation

Once a device or data source is identified, the next step is to preserve the data in its original state. This is where the concept of "forensic imaging" comes into play. A forensic investigator creates a bit-by-bit, identical copy of the entire storage medium. This "forensic image" is a perfect clone of the original data, including hidden files, deleted files, and unallocated space. The original device is then secured and stored as a pristine piece of evidence, and all subsequent analysis is performed on the copy. This practice ensures the integrity of the original evidence, maintaining the chain of custody.

For devices that are powered on ("live"), the process is more complex. You can't simply unplug the device as this could destroy volatile data like that in the RAM (Random Access Memory) or active network connections. In these situations, investigators must carefully acquire the volatile data first before shutting down the system and creating a forensic image of the non-volatile data.

3.Analysis

This is the phase where the investigator sifts through the preserved data to find and interpret relevant evidence. This involves a variety of specialized techniques and tools:

File Carving/Deleted File Recovery: Recovering files that have been deleted but still exist in fragments on the storage medium.
Keyword Searches: Using specific keywords and phrases to locate relevant documents, emails, and chat logs.
Timeline Analysis: Reconstructing a chronological sequence of events based on timestamps from various files and system logs.
Cross-Drive Analysis: Correlating data across multiple devices to establish connections between different pieces of evidence or individuals.
Malware Analysis: Analyzing malicious software to understand its functionality, origin, and impact on the system.

Tools and Best Practices

A digital forensics investigator relies on a suite of specialized hardware and software tools to perform these tasks effectively.

Essential Tools

Forensics Software: Tools like EnCase, FTK (Forensic Toolkit), and Autopsy are industry standards for creating forensic images and analyzing data. They provide a comprehensive environment for examining file systems, recovering data, and generating reports.
Write Blockers: These hardware devices are used during the imaging process. They physically prevent any data from being written to the original storage device, ensuring its integrity is maintained.
Faraday Bags: These are pouches made of conductive fabric that block all wireless signals (cellular, Wi-Fi, Bluetooth). They are crucial for isolating mobile devices from the network to prevent remote wiping or data alteration.

Key Best Practices

Maintain the Chain of Custody: Meticulous documentation is paramount. Every step, from the seizure of the device to the final analysis, must be logged. This includes who handled the evidence, when they handled it, and what they did with it. This proves the evidence hasn't been tampered with.
Work on a Copy, Not the Original: Always analyze a forensic image, never the original device. This is the golden rule of digital forensics and is critical for ensuring evidence admissibility in court.
Have Legal Authority: Before seizing or analyzing any device, investigators must have the proper legal authorization, such as a search warrant or court order. The legality of the search can be a major factor in whether the evidence is admissible.
Be Aware of Volatile Data: Always prioritize the collection of volatile data from a running system before powering it down.

3. Documentation and Presentation

The final two stages are just as important as the first three.

Documentation

This phase involves creating a comprehensive report of the entire investigation. The report must be clear, concise, and understandable to non-technical individuals, like lawyers or jury members. It should include:

Details of the case.
The methodology used.
A log of all actions taken.
A description of the evidence found.
The conclusions drawn from the analysis.

Presentation

The final stage is presenting the findings in a legal or administrative setting. The investigator may be required to testify in court as an expert witness, explaining the technical findings in a clear and compelling manner. A strong, well-documented report is the foundation for this testimony, helping to ensure the successful prosecution of the cybercriminal.