Course 13 - Network Forensics | Episode 7: Web Traffic Analysis and Browser Forensics: Handshakes, DNSSEC, and Cookies

In this lesson, you’ll learn about:How to identify and analyze web traffic using network forensics techniquesThe role of DNSSEC in securing DNS infrastructureBrowser forensics across IE, Firefox, Chrome, Edge, and SafariHow history files, caches, and artifacts differ between browsersThe forensic value of cookies and how they are stored and analyzed1. Network Traffic Analysis Fundamentals A core skill in network forensics is the ability to recognize and interpret the TCP three-way handshake.This handshake—SYN → SYN/ACK → ACK—is the best indicator of:A new connection formingImpending data transferThe type of communication taking placeIdentifying Web TrafficPort 80 typically indicates HTTP web trafficA GET request usually confirms thisPort 23 indicates Telnet, which sends data in plaintextOlder packet captures may reveal metadata about the remote system:Example: Seeing IIS5 suggests the server was running Windows 2000Being able to identify OS fingerprints and protocol behavior is critical for traffic analysis. 2. Enhancing Security with DNSSEC DNSSEC (DNS Security Extensions) is recommended to strengthen DNS infrastructure. Key Benefits of DNSSECCryptographic signing of records prevents unauthorized changesMakes DNS poisoning or zone file tampering extremely difficultIf a compromise occurs, DNSSEC provides detailed forensic evidenceSignaturesValidation failuresTampered data tracesDNSSEC does not fix DNS’s entire design, but it dramatically increases integrity and trust. 3. Browser and Client-Side Forensics Different browsers store history, cache, and session data in different formats and file locations. These paths also vary across operating systems. Understanding these artifacts is essential for analyzing user activity. Internet Explorer (IE) Key artifact: index.datA binary file that logs significant browsing activityCannot be opened with Notepad or standard editorsRequires specialized tools or index.dat viewersOlder systems stored IE artifacts under:Local Settings\Temporary Internet FilesIE’s structure makes it rich in recoverable artifacts even after attempted deletion. Firefox Key artifact: history.datStored in ASCII format, viewable in plain textEasier to read than IE’s binary formatHowever, it does not directly link visited sites with cached pagesReconstruction of user view is harderStored under the user profile in Application Data > Firefox foldersFirefox’s structured but separated data can make page reconstruction challenging. 4. The Forensic Significance of Cookies A cookie is a small text file saved by websites to store:Language preferencesActivitySession identifiersVisit frequencyCookies are critical in forensics because they persist even when:History is deletedCache is wipedPrivate browsing was usedWhy Cookies MatterShow repeated visits vs. “accidental” single accessReveal behavior and browsing patternsTie activity to specific sessions or visitsHelp reconstruct long-term user engagementCookie CharacteristicsMinimum expected size: 4 KBContain six components (e.g., name, value, expiration date, domain, path, flags)Session cookies: deleted when browser closesPersistent cookies: stored long-term and replayed on revisitOften used for access control and session managementTampering and Manipulation Cookies can be intercepted or modified using tools such as:Burp SuiteBrowser developer toolsExamples include:Modifying session cookiesChanging identifiersInfluencing e-commerce machine-learning systems that adjust prices based on user interest/visit frequencyStorage Locations Each browser (IE, Edge, Chrome, Firefox, Safari) stores cookies in different folders and formats, often encoded or indexed. Precise knowledge of these locations is required during forensic acquisition or investigation.You can listen and download our episodes for free on more than 10 different platforms:https://linktr.ee/cybercode_academy