Forensic Report: Examination Procedures (en)

5. Digital Forensic Examination Procedures

Digital forensic examination procedures are a series of systematic steps taken to collect, analyze, and preserve digital evidence from a device or system. The goal is to obtain relevant information for an investigation, whether criminal, civil, or internal corporate.

5.1 Evidence Receipt

• Date and Time of Receipt: Accurate records of when evidence is received are crucial for maintaining the chain of custody and the integrity of the evidence.
• Condition of Evidence: Document the physical condition of the device (e.g., cracked, damaged, signs of tampering), as well as its power state (on, off).
• Initial Steps:
  • Documentation: Make detailed notes of all device details, including brand, model, serial number, and included accessories.
  • Photography: Take photos of the device from various angles before and after the examination. This is useful for documenting the initial condition and any changes that occur during the examination process.
  • Video: Record a short video when unpacking the device to visually document the process.

5.2 Acquisition Process

• Acquisition Methods:
  • Live Acquisition: Copying data directly from a device that is currently operational. This method is useful for capturing volatile data (easily lost) such as memory.
  • Static Acquisition: Copying data from a device that has been powered off. This method is more commonly used because it does not disturb the device's condition.
  • Disk Imaging: Creating a bit-by-bit copy of the entire storage medium. This is the most recommended method to maintain data integrity.
• Integrity Verification:
  • Hash Value: Calculate the hash value of both the original data and its copy. Compare the two hash values to ensure that the copy made is identical to the original.
  • Checksum: Calculate the checksum of the data to verify data integrity.

5.3 Data Analysis

• Types of Analysis:
  • File System Analysis: Identifying the type of file system used, directory structure, and existing files.
  • Network Analysis: Analyzing network activities previously performed by the device, including IP addresses, ports, and protocols used.
  • Malware Analysis: Searching for the presence of malware, viruses, or other malicious programs.
  • Email Analysis: Analyzing emails present on the device, including email content, attachments, and metadata.
  • Web History Analysis: Analyzing the web browsing history previously conducted.
• Tools and Techniques:
  • Forensic Tools: Utilizing various forensic software such as EnCase, FTK Imager, Autopsy, and Sleuth Kit.
  • Scripting: Using programming languages like Python to perform more complex analyses.

5.4 Documentation

• Examination Report: Create a detailed report regarding the entire examination process, from evidence receipt to analysis results.
• Screenshots: Take screenshots of important analysis results.
• Log: Record all activities conducted during the examination process in a log file.
• Chain of Custody: Document the chain of custody of the evidence completely, including who held the evidence, when, and where.

Important: The entire examination process must be conducted according to established procedures and forensic ethical standards to maintain evidence integrity and avoid contamination.

Note: The explanation above provides an overview of digital forensic examination procedures. Actual procedures may vary depending on the type of device, operating system, and investigation objectives.

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