Network forensics is a sub-branch of digital forensics relating to the monitoring and analysis of computer network traffic for the purposes of information gathering, legal evidence, or intrusion detection.
Unlike other areas of digital forensics, network investigations deal with volatile and dynamic information. Network traffic is transmitted and then lost, so network forensics is often a pro-active investigation.
WHAT IS A PCAP FILE
Unix-like systems implement pcap in the libpcap library; Windows uses a port of libpcap known as WinPcap.
It is a Data file created by Wireshark (formerly Ethereal), a free program used for network analysis; contains network packet data created during a live network capture; used for “packet sniffing” and analyzing data network characteristics; can be analyzed using software that includes the libpcap or WinPcap libraries
FORENSIC ANALYSIS MEDIUM
Well, we will be using a tool known as XPLICO, xplico is an open source NFAT (Network Forensic Analysis Tool), the goal of Xplico is extracted from an internet traffic capture the application’s data contained.
For example, from a pcap file Xplico extracts each email (POP, IMAP, and SMTP protocols), all HTTP contents, each VoIP call (SIP), FTP, TFTP, and so on
To know more about XPLICO tool click here
PROCEDURE – Network Forensics
- Open the terminal and start the xplico service by the command “etc/init.d/xplico start” or “service xplico start”
- Go to browser and type the following url “ http://localhost:9876/ ”By the following credentials login to the xplico web interface
“Username : xplico”
“Password : xplico”
- Click on the new case and give it a name and a reference number and click create.
- Click on the case name (eg:test)
- Click on new session and give it a name (eg: analysis-1) and click on create
- Click on the name of the session (eg analysis-1)
- Click on browse and browse your PCAP file
- After loading it on xplico interface click on upload button
- After the uploading process the tool will start decoding
- After the decoding process, you will get the status as shown below
- Now you can get the overview of analysis and in the left pane you will have the option to navigate to the analysis done (below is the screenshot of the graph of DNS messages).
XPLICO – This tool is simple and easy to use also it does an intense analysis of the Packet Capture –PCAP file, This tool pre-loaded in many penetration testing Linux flavors such as KALI LINUX, PARROT OS, DEFT, Security Onion, Backbox, Pentooetc.