Disk, Memory, and Network Forensics

Lecture Note: Disk, Memory, and Network Forensics

Introduction

Digital forensics involves the collection, preservation, analysis, and presentation of electronic evidence. Three critical areas in this field are disk forensics, memory forensics, and network forensics. Each focuses on a different data source, but together they provide a complete picture of an incident.

Disk Forensics

Focus: Storage media such as hard drives, SSDs, and USBs.
Objective: Recover and analyze data to determine user actions and system events.

Key Tasks:

• Drive Imaging: Create a bit-by-bit copy of storage media without altering original data.
• Data Recovery: Retrieve deleted files, hidden partitions, and metadata.
• File System Examination: Analyze file systems like NTFS, FAT, or EXT to identify file structures and access patterns.
• Artifact Analysis: Identify installed programs, system logs, and timestamps to reconstruct user activity.

Use Cases:

• Investigating unauthorized access or insider threats.
• Detecting data exfiltration and file tampering.
• Uncovering malware persistence mechanisms.

Memory Forensics

Focus: Volatile memory (RAM).
Objective: Capture and analyze live system data that is lost when the system is powered off.

Key Tasks:

• Memory Acquisition: Capture the system’s RAM using tools like Volatility or Rekall.
• Process Analysis: Identify active and hidden processes, open network connections, and injected code.
• Credential Extraction: Recover encryption keys, passwords, and authentication tokens.
• Malware Detection: Detect rootkits, fileless malware, or injected code running in memory.

Use Cases:

• Analyzing live system attacks.
• Detecting advanced persistent threats (APTs).
• Investigating system compromise without disk artifacts.

Network Forensics

Focus: Data transmitted across a network.
Objective: Capture, record, and analyze network traffic to detect malicious activities and reconstruct communication patterns.

Key Tasks:

• Packet Capture: Record data packets using tools like Wireshark, tcpdump, or Zeek (Bro).
• Traffic Analysis: Examine logs, sessions, and flow data to identify abnormal behavior.
• Incident Tracing: Track unauthorized connections, command-and-control communications, and data exfiltration routes.

Use Cases:

• Detecting intrusion attempts and data breaches.
• Analyzing phishing and malware command channels.
• Reconstructing attack paths and communication timelines.

Integration of Forensic Disciplines

Disk, memory, and network forensics complement one another:

• Disk forensics reveals what was stored.
• Memory forensics uncovers what was running.
• Network forensics shows what was communicated.

Together, they provide a holistic understanding of cyber incidents and support accurate reconstruction of attack scenarios.