Tools and Techniques (en)

Network Investigation is the process of collecting, analyzing, and interpreting network data to identify, understand, and respond to cybersecurity incidents. In the context of IT forensics, network investigation aims to collect digital evidence that can be used to trace the origin of an attack, identify perpetrators, and reconstruct the events that occurred.

Tools and Techniques

Packet Capture

• Definition: The process of capturing and storing all data transmitted over a network in the form of data packets.

• Objectives:
  • Identify suspicious traffic.
  • Analyze packet contents for signs of an attack.
  • Reconstruct network connections.

• Tools:
  • Wireshark: One of the most popular tools for capturing and analyzing packets, offering a user-friendly interface and comprehensive features.
  • Tcpdump: A powerful command-line tool for capturing packets with high flexibility.
  • Network Monitor: Available on several operating systems, such as Windows, for performing low-level captures.

Network Traffic Analysis

• Definition: The process of analyzing captured data to identify patterns, anomalies, and unusual activities.

• Objectives:
  • Detect attacks such as scanning, intrusion, and data exfiltration.
  • Identify sources of suspicious traffic.
  • Measure network performance.

• Techniques:
  • Statistical Analysis: Calculating averages, standard deviations, and other metrics to identify anomalies.
  • Protocol Analysis: Analyzing packet headers to understand the protocols used and look for configuration errors.
  • Payload Analysis: Analyzing packet contents for signs of malware or stolen data.

• Tools:
  • Wireshark: In addition to capturing, Wireshark also provides various features for traffic analysis.
  • Elasticsearch, Kibana, and Beats (ELK Stack): This combination of tools allows you to collect, analyze, and visualize network data on a large scale.
  • Security Information and Event Management (SIEM): SIEM tools collect logs from various sources, including networks, to provide a comprehensive view of security.

DNS Analysis

• Definition: The process of analyzing DNS traffic to identify domains, servers, and activities related to an incident.

• Objectives:
  • Identify malicious domains accessed by systems.
  • Track communication with botnets or command and control servers.
  • Identify DNS tunneling used to hide traffic.

• Tools:
  • Wireshark: Can be used to capture and analyze DNS traffic.
  • Dnslog: A service that allows you to create unique domains to track DNS requests.
  • Farsight Security: Provides a large public DNS database for analysis.

Network Investigation Process

1. Incident Identification: Detecting anomalies or suspicious activities.
2. Data Collection: Performing packet capture at relevant points in the network.
3. Data Analysis: Analyzing captured data using various techniques and tools.
4. Data Correlation: Linking data obtained from various sources to gain a more comprehensive picture.
5. Reporting: Compiling a detailed report on the investigation results, including findings, analysis, and recommendations.

Important:

• Evidence Preservation: Ensure that the collected data is not contaminated and can be accepted as evidence in court.
• Chain of Custody: Document every step in the investigation process to maintain evidence integrity.
• Efficiency: Use appropriate tools and techniques to expedite the investigation process.

Conclusion

Network investigation is a critical component of IT forensics. By understanding the right tools and techniques, you can effectively collect and analyze network data to uncover the root causes of cybersecurity incidents.

Interesting Links

• Forensic: IT