Network forensics has become an essential aspect of digital forensics in recent years. The examination of a network can provide critical information about how a company functions and the activities that have taken place on its systems. To conduct a successful network forensic examination, following the correct steps and using the appropriate tools is essential.
This article will discuss the steps involved in network forensics and the different types of tools available for use. We will also explore the difference between computer forensics and network forensics and explain why both are essential for investigating cybercrime.
What is Network Forensics?
Network forensics investigates network traffic patterns and data acquired while in transit in a networked environment. It involves examining traffic data, logs, and other data that can be used to investigate cybercrime, network security incidents, and data breaches. A network forensic examination aims to identify and preserve digital evidence that can be used in a court of law.
By analyzing records of network events provided by network forensics, law enforcement agencies and cybercrime investigators can piece together communications and timelines to better understand what happened during a crime or other mysterious event (Keumars, 2021). Analysts check for evidence of human communication, file tampering, and keyword usage, among other indicators.
Network Forensics Examination Steps
When conducting a network forensic examination, it’s important to follow appropriate steps to ensure that all evidence is collected and preserved. Here are the seven steps for the forensic examination.
Identification
The first step of any forensic examination is to identify the scope of the investigation. This will help determine what data needs to be collected and which tools will be required. The identification process, which leads to the case’s resolution, significantly impacts the following steps.
Preservation
After the scope of the investigation has been determined, it’s essential to take steps to preserve the evidence. This includes making copies of any relevant data and storing it in a safe location. All data should be collected in a manner that preserves its integrity and chain of custody. The data is isolated to ensure that the digital evidence cannot be tampered with. This also prevents anyone from using the device. You can use various applications for this task, such as Autopsy and Encase.
Collection
The next step is to collect the data, which can be done manually or through automated tools. In most cases, it’s best to use both methods. The manual collection involves going through each file and logging relevant information. Automated collection, on the other
hand, uses specialized software to scan network traffic and extract data. Collection can also be done through packet capture, full-packet capture, and NetFlow analysis.
Examination
Once the data has been collected, it’s time to examine it. This step involves analyzing the data to look for patterns or anomalies indicative of a security incident. Any visible data is tracked along with the metadata (GeeksforGeeks, 2022). The examiner also checks for any indicators of compromise (IOCs). IOCs are specific characteristics that can be used to identify an intrusion or malware. They can include IP addresses, file hashes, and domain names.
Analysis
Investigators use the data they find in packets of network traffic to determine what happened and why it’s important. The Security information and event management (SIEM) software tracks network activity. The SIEM solutions also analyze log and event data in real-time to enable threat monitoring, event correlation, and incident response (Lifars, 2020).
Presentation
The sixth step is to present the findings. This can be done in a report or presentation. The report should include all relevant information, such as evidence of an intrusion, malicious activity, or data exfiltration. It should also include any recommendations for improving security. The presentation should be clear and concise, highlighting the most important findings. Investigators should also be prepared to answer questions from stakeholders.
Incident Response
Information obtained to validate and assess an attack or intrusion triggers a response. The goal is to limit damage and performance impact, identify the root cause, eradicate it, and take steps to prevent future incidents. The plan includes minimizing downtime, data loss, and organizational impact.
Types of Tools Available
Several cyber forensic tools can be used for network forensics. These tools collect data from various sources, including routers, switches, and servers. Let’s have a look at some of them below:
- Packet capture tools: These tools capture and store network data for later analysis. Examples include Wireshark, TCPDump, and Arkime (Jenifa, 2022).
- Full-packet capture tools: As the name suggests, these tools capture and store all data passing through a network interface. Examples include NetWitness Investigator and RSA NetWitness Platform.
- Log analysis tools: Splunk, ELK Stack, and Graylog help analyze log files from devices on the network.
- NetFlow analysis tools: These tools analyze NetFlow data to identify traffic patterns and anomalies. Examples include SolarWinds NetFlow Traffic Analyzer and ManageEngine NetFlow Analyzer.
- SIEM tools: These provide a centralized view of log data from multiple devices on the network. Examples include Splunk Enterprise Security and IBM QRadar (Keary, 2022).
- Digital forensics platforms: RSA NetWitness Platform and Splunk Enterprise Security, among other tools, provide a complete solution for network forensics, including data collection, analysis, and reporting.
- Intrusion detection system tools: These detect and alert suspicious activity on the network. Examples include Snort and Suricata.
The Difference Between Computer Forensics and Network Forensics
While both computer and network forensics involve examining data, several key differences exist between the two fields.
Point of Difference
1. Type of data they focus on
2. The scope of the two disciplines
3. Live versus offline data
4. Incidents investigated
5. Tools used
Computer Forensics
Focuses on data stored on computers.
It is often used in criminal cases
Generally, it involves examining data stored offline.
Computer forensics is more often used in fraud or employee misconduct cases.
It can be conducted using standard forensic tools because examination involves stored/offline data.
Network Forensics
Focuses on examining data transmitted over networks.
It is used in both criminal and civil cases.
It can be used to examine live data.
Network forensics is typically used to investigate incidents like network intrusion or data theft.
It often requires specialized tools since the data examined is live and in transit over networks.
In general, network forensics is a more specialized field than computer forensics. However, the skills and knowledge required for both fields are similar. Investigators need to understand networking concepts well and be familiar with using specialized tools.
Individuals with an in-depth understanding of network forensics and the ability to analyze and protect network infrastructure are in demand. The Computer Hacking Forensic Investigator program (C|HFI) provides you with the expertise and knowledge necessary to
perform computer forensics investigations and become a Computer Hacking Forensic Investigator and become a Certified Hacking and Forensic Investigator.
