performing-network-forensics-with-wireshark

name	performing-network-forensics-with-wireshark
description	Capture and analyze network traffic using Wireshark and tshark to reconstruct network events, extract artifacts, and identify malicious communications.
domain	cybersecurity
subdomain	digital-forensics
tags	["forensics","network-forensics","wireshark","pcap","packet-analysis","traffic-analysis"]
version	1.0
author	mahipal
license	Apache-2.0
nist_csf	["RS.AN-01","RS.AN-03","DE.AE-02","RS.MA-01"]

Performing Network Forensics with Wireshark

When to Use

• When analyzing captured network traffic (PCAP files) from a security incident
• For identifying command-and-control (C2) communications in captured traffic
• When reconstructing data exfiltration activities from packet captures
• During malware analysis to identify network indicators of compromise
• For extracting files, credentials, and artifacts transferred over the network

Detection Gaps & Validation

A PCAP only contains what the sensor actually saw, decrypted to the depth your tooling supports. Account for these blind spots:

• Capture truncation and drops. A snaplen below the MTU (tcpdump -s too small) gives you headers without payloads, so --export-objects silently produces nothing. Run capinfos and check for dropped packets, snaplen, and whether the duration covers the incident window — "no files extracted" is often truncation, not absence. Missing one direction (asymmetric routing/SPAN) breaks stream reassembly.
• Encrypted payloads hide the content, not the metadata. TLS 1.3/QUIC, DoH/DoT, and SSH mean you can't read bodies without keys. Pivot to what stays visible: SNI (often, but ECH/encrypted ClientHello blocks it), JA3/JA3S fingerprints, certificate issuers/validity, connection sizes, and timing. Don't conclude traffic is benign just because you can't decrypt it.
• C2 hides in normal-looking flows. Beaconing with jitter defeats fixed-interval filters; domain fronting and traffic over 443/53 blend in. Validate a suspected beacon by computing inter-arrival variance across the whole capture and correlating the destination with endpoint process/DNS logs, not a single frame.time_delta filter.
• Cross-corroborate and verify, don't trust one heuristic. Reassembled TCP streams can be incomplete if SYN/retransmits are missing; carved files may be partial. Hash every extracted object and check it against threat intel/VirusTotal before calling it malware, and confirm the file actually transferred (response 200 + content-length) versus an aborted request.
• Interpretation false positives. Long/random DNS labels are frequently CDNs, AV telemetry, and analytics — not always tunneling; self-signed certs are common on internal services. NetworkMiner OS/port guesses are heuristic. Verify clock/timezone of the capture host before building a timeline, and treat plaintext "credentials" as candidates until you confirm the service and account.

Prerequisites

• Wireshark or tshark installed for packet analysis
• PCAP/PCAPNG files from network captures (tcpdump, Wireshark, network TAP)