--- name: performing-network-forensics-with-wireshark-8486ba859c3b description: Capture and analyze network traffic using Wireshark and tshark to reconstruct network events from PCAP/PCAPNG files, extract transferred files and credentials, and identify command-and-control communications. Use when analyzing captured traffic from a security incident, reconstructing data exfiltration, or finding network indicators of compromise during malware analysis. 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-03 - DE.AE-02 - RS.MA-01 mitre_attack: - T1005 - T1074 - T1119 - T1070 - T1059 --- # 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 ## Prerequisites - Wireshark or tshark installed for packet analysis - PCAP/PCAPNG files from network captures (tcpdump, Wireshark, network TAP) - NetworkMiner for automated artifact extraction - Sufficient RAM for large capture files (1GB+ PCAPs need 8GB+ RAM) - Understanding of TCP/IP, HTTP, DNS, TLS protocols - GeoIP databases for IP geolocation ## Workflow ### Step 1: Prepare and Validate the Capture File ```bash # Install Wireshark and tshark sudo apt-get install wireshark tshark # Verify the PCAP file capinfos /cases/case-2024-001/network/capture.pcap # Output includes: file type, packet count, capture duration, data size # Example output: # File name: capture.pcap # File type: Wireshark/tcpdump/... - pcap # Number of packets: 1,245,678 # File size: 856 MB # Data size: 823 MB # Capture duration: 3600.123456 seconds # First packet time: 2024-01-15 14:00:00.000000 # Last packet time: 2024-01-15 15:00:00.123456 # Hash the PCAP for integrity sha256sum /cases/case-2024-001/network/capture.pcap \ > /cases/case-2024-001/network/pcap_hash.txt # Get a protocol hierarchy statistics overview tshark -r /cases/case-2024-001/network/capture.pcap -q -z io,phs ``` ### Step 2: Filter and Identify Suspicious Traffic ```bash # Extract conversation statistics tshark -r /cases/case-2024-001/network/capture.pcap -q -z conv,tcp # Find top talkers by bytes transferred tshark -r /cases/case-2024-001/network/capture.pcap -q -z endpoints,ip \ | sort -t$'\t' -k3 -rn | head -20 # Filter for DNS queries (potential C2 or exfiltration) tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "dns.qr == 0" \ -T fields -e frame.time -e ip.src -e dns.qry.name \ > /cases/case-2024-001/analysis/dns_queries.txt # Find DNS queries to unusual TLDs or long domain names (DNS tunneling) tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "dns.qr == 0 && dns.qry.name matches \"[a-z0-9]{30,}\"" \ -T fields -e frame.time -e ip.src -e dns.qry.name \ > /cases/case-2024-001/analysis/suspicious_dns.txt # Filter HTTP traffic tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "http.request" \ -T fields -e frame.time -e ip.src -e ip.dst -e http.request.method \ -e http.host -e http.request.uri -e http.user_agent \ > /cases/case-2024-001/analysis/http_requests.txt # Find connections to known malicious ports tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "tcp.dstport == 4444 || tcp.dstport == 8080 || tcp.dstport == 1337 || tcp.dstport == 6667" \ -T fields -e frame.time -e ip.src -e ip.dst -e tcp.dstport \ > /cases/case-2024-001/analysis/suspicious_ports.txt # Detect beaconing patterns (regular interval connections) tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "ip.dst == 185.0.0.1" \ -T fields -e frame.time_epoch \ > /tmp/beacon_times.txt ``` ### Step 3: Extract Files and Objects from Traffic ```bash # Export HTTP objects (files transferred over HTTP) tshark -r /cases/case-2024-001/network/capture.pcap \ --export-objects http,/cases/case-2024-001/analysis/http_objects/ # Export SMB objects tshark -r /cases/case-2024-001/network/capture.pcap \ --export-objects smb,/cases/case-2024-001/analysis/smb_objects/ # Export DICOM objects (medical imaging) tshark -r /cases/case-2024-001/network/capture.pcap \ --export-objects dicom,/cases/case-2024-001/analysis/dicom_objects/ # Export FTP data transfers tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "ftp-data" \ -T fields -e ftp-data.data \ --export-objects ftp-data,/cases/case-2024-001/analysis/ftp_objects/ # Hash all extracted objects find /cases/case-2024-001/analysis/http_objects/ -type f -exec sha256sum {} \; \ > /cases/case-2024-001/analysis/extracted_file_hashes.txt # Check extracted file hashes against VirusTotal while read hash filepath; do echo "Checking $filepath ($hash)" curl -s "https://www.virustotal.com/api/v3/files/$hash" \ -H "x-apikey: YOUR_API_KEY" | python3 -c " import json,sys data=json.load(sys.stdin) if 'data' in data: stats=data['data']['attributes']['last_analysis_stats'] print(f' Malicious: {stats[\"malicious\"]}, Undetected: {stats[\"undetected\"]}') else: print(' Not found on VT') " done < /cases/case-2024-001/analysis/extracted_file_hashes.txt ``` ### Step 4: Reconstruct TCP Streams and Sessions ```bash # Follow a specific TCP stream (stream index 42) tshark -r /cases/case-2024-001/network/capture.pcap \ -q -z "follow,tcp,ascii,42" \ > /cases/case-2024-001/analysis/stream_42.txt # Extract all HTTP request-response pairs for a suspicious host tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "http && ip.addr == 185.0.0.1" \ -T fields -e frame.time -e http.request.method -e http.host \ -e http.request.uri -e http.response.code -e http.content_length \ > /cases/case-2024-001/analysis/suspicious_http.txt # Extract TLS/SSL certificate information tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "tls.handshake.type == 11" \ -T fields -e ip.dst -e tls.handshake.certificate \ > /cases/case-2024-001/analysis/tls_certs.txt # Extract TLS SNI (Server Name Indication) values tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "tls.handshake.extensions_server_name" \ -T fields -e frame.time -e ip.src -e ip.dst \ -e tls.handshake.extensions_server_name \ > /cases/case-2024-001/analysis/tls_sni.txt # Extract credentials from unencrypted protocols tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "ftp.request.command == \"USER\" || ftp.request.command == \"PASS\"" \ -T fields -e frame.time -e ip.src -e ftp.request.command -e ftp.request.arg tshark -r /cases/case-2024-001/network/capture.pcap \ -Y "http.authorization" \ -T fields -e frame.time -e ip.src -e http.host -e http.authorization ``` ### Step 5: Use NetworkMiner for Automated Analysis ```bash # Install NetworkMiner (Mono required on Linux) sudo apt-get install mono-complete wget https://www.netresec.com/?download=NetworkMiner -O NetworkMiner.zip unzip NetworkMiner.zip -d /opt/NetworkMiner/ # Run NetworkMiner mono /opt/NetworkMiner/NetworkMiner.exe /cases/case-2024-001/network/capture.pcap # NetworkMiner automatically extracts: # - Host inventory (OS fingerprinting, open ports) # - Files transferred over HTTP, FTP, SMB, TFTP # - Images from web traffic # - Credentials (plaintext and NTLM hashes) # - DNS records # - Session parameters # - Anomalies and alerts ``` ### Step 6: Generate Network Forensics Report ```bash # Compile findings cat << 'EOF' > /cases/case-2024-001/analysis/network_forensics_report.txt NETWORK FORENSICS ANALYSIS REPORT =================================== Case: 2024-001 Capture File: capture.pcap (856 MB, 1,245,678 packets) Capture Period: 2024-01-15 14:00 to 15:00 UTC Analyst: [Examiner Name] TRAFFIC OVERVIEW: Total packets: 1,245,678 Unique source IPs: 45 Unique destination IPs: 234 Protocols: TCP (78%), UDP (18%), ICMP (2%), Other (2%) C2 COMMUNICATION: Destination: 185.0.0.1:443 Beaconing interval: ~60 seconds Total connections: 58 Data transferred: 4.2 MB outbound, 12.3 MB inbound TLS SNI: update-service.malware-c2.com EXFILTRATION: Method: HTTPS POST to 185.0.0.1 Volume: 4.2 MB over 45 minutes Files: 3 ZIP archives extracted from HTTP objects DNS TUNNELING: Suspicious queries to: data.evil-dns.com Average subdomain length: 45 characters Query count: 1,234 (normal baseline: 50) EOF ``` ## Key Concepts | Concept | Description | |---------|-------------| | PCAP/PCAPNG | Packet capture file formats storing raw network traffic | | TCP stream | Complete bidirectional communication between two endpoints | | Deep packet inspection | Analysis of packet payload content beyond header information | | Beaconing | Regular-interval callbacks from malware to C2 servers | | DNS tunneling | Encoding data within DNS queries for covert exfiltration | | TLS/SNI | Server Name Indication revealing the target hostname in encrypted connections | | Network flow | Summary of communication between endpoints (IPs, ports, bytes, duration) | | Protocol hierarchy | Statistical breakdown of protocols present in a capture | ## Tools & Systems | Tool | Purpose | |------|---------| | Wireshark | GUI-based packet analyzer with deep protocol dissection | | tshark | Command-line version of Wireshark for scripted analysis | | NetworkMiner | Automated network forensic analysis and file extraction | | tcpdump | Command-line packet capture utility | | zeek (Bro) | Network security monitor generating structured connection logs | | ngrep | Network grep for pattern matching in packet content | | capinfos | PCAP file statistics and metadata utility | | mergecap | Merge multiple PCAP files into a single capture | ## Common Scenarios **Scenario 1: Malware C2 Communication Analysis** Load PCAP in Wireshark, identify beaconing patterns to external IPs, examine TLS certificates for self-signed or unusual issuers, extract HTTP POST data containing encoded commands, correlate C2 IPs with threat intelligence feeds. **Scenario 2: Data Exfiltration Detection** Analyze traffic statistics for unusually large outbound transfers, examine DNS query lengths for DNS tunneling indicators, track FTP and HTTP file uploads to external servers, reconstruct exfiltrated files from packet data. **Scenario 3: Lateral Movement in Enterprise Network** Filter for SMB, RDP, WMI, and PSExec traffic between internal hosts, identify credential usage patterns across multiple systems, trace the propagation path of the attacker through the network, correlate with Windows Event Log authentication events. **Scenario 4: Web Application Attack Reconstruction** Filter HTTP traffic to the web server, identify SQL injection, XSS, and directory traversal attempts, follow the TCP stream of the successful exploit, extract uploaded webshells or payloads, document the attack chain for the incident report. ## Output Format ``` Network Forensics Summary: Capture: capture.pcap Duration: 1 hour (14:00-15:00 UTC, 2024-01-15) Packets: 1,245,678 | Size: 856 MB Top Suspicious Connections: 192.168.1.50 -> 185.0.0.1:443 (C2, 58 connections, 4.2MB out) 192.168.1.50 -> 10.0.0.25:445 (SMB lateral movement) 192.168.1.50 -> 10.0.0.30:3389 (RDP lateral movement) Extracted Artifacts: Files: 23 (3 malicious per VT) Credentials: 2 plaintext FTP logins DNS Queries: 1,234 suspicious (possible tunneling) TLS Certs: 5 self-signed certificates IOCs Identified: IPs: 185.0.0.1, 203.0.113.50 Domains: update-service.malware-c2.com, data.evil-dns.com Hashes: 3 file hashes flagged as malware ``` --- Source attribution: costrict-plugins-repo Original project: https://github.com/costrict-plugins-repo/mukul975-anthropic-cybersecurity-skills-cybersecurity-skills/blob/1b344d155f00bae5cf27d8eba9508e8f5050d904/skills/performing-network-forensics-with-wireshark/SKILL.md License: Apache-2.0 License information: https://www.apache.org/licenses/LICENSE-2.0 Original upstream instructions; downloaded from Dave AI. ## Upstream license notice Apache License Version 2.0, January 2004 http://www.apache.org/licenses/ TERMS AND CONDITIONS FOR USE, REPRODUCTION, AND DISTRIBUTION 1. Definitions. "License" shall mean the terms and conditions for use, reproduction, and distribution as defined by Sections 1 through 9 of this document. "Licensor" shall mean the copyright owner or entity authorized by the copyright owner that is granting the License. "Legal Entity" shall mean the union of the acting entity and all other entities that control, are controlled by, or are under common control with that entity. For the purposes of this definition, "control" means (i) the power, direct or indirect, to cause the direction or management of such entity, whether by contract or otherwise, or (ii) ownership of fifty percent (50%) or more of the outstanding shares, or (iii) beneficial ownership of such entity. "You" (or "Your") shall mean an individual or Legal Entity exercising permissions granted by this License. "Source" form shall mean the preferred form for making modifications, including but not limited to software source code, documentation source, and configuration files. "Object" form shall mean any form resulting from mechanical transformation or translation of a Source form, including but not limited to compiled object code, generated documentation, and conversions to other media types. "Work" shall mean the work of authorship, whether in Source or Object form, made available under the License, as indicated by a copyright notice that is included in or attached to the work (an example is provided in the Appendix below). "Derivative Works" shall mean any work, whether in Source or Object form, that is based on (or derived from) the Work and for which the editorial revisions, annotations, elaborations, or other modifications represent, as a whole, an original work of authorship. For the purposes of this License, Derivative Works shall not include works that remain separable from, or merely link (or bind by name) to the interfaces of, the Work and Derivative Works thereof. "Contribution" shall mean any work of authorship, including the original version of the Work and any modifications or additions to that Work or Derivative Works thereof, that is intentionally submitted to the Licensor for inclusion in the Work by the copyright owner or by an individual or Legal Entity authorized to submit on behalf of the copyright owner. For the purposes of this definition, "submitted" means any form of electronic, verbal, or written communication sent to the Licensor or its representatives, including but not limited to communication on electronic mailing lists, source code control systems, and issue tracking systems that are managed by, or on behalf of, the Licensor for the purpose of discussing and improving the Work, but excluding communication that is conspicuously marked or otherwise designated in writing by the copyright owner as "Not a Contribution." "Contributor" shall mean Licensor and any individual or Legal Entity on behalf of whom a Contribution has been received by the Licensor and subsequently incorporated within the Work. 2. Grant of Copyright License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable copyright license to reproduce, prepare Derivative Works of, publicly display, publicly perform, sublicense, and distribute the Work and such Derivative Works in Source or Object form. 3. Grant of Patent License. Subject to the terms and conditions of this License, each Contributor hereby grants to You a perpetual, worldwide, non-exclusive, no-charge, royalty-free, irrevocable (except as stated in this section) patent license to make, have made, use, offer to sell, sell, import, and otherwise transfer the Work, where such license applies only to those patent claims licensable by such Contributor that are necessarily infringed by their Contribution(s) alone or by combination of their Contribution(s) with the Work to which such Contribution(s) was submitted. If You institute patent litigation against any entity (including a cross-claim or counterclaim in a lawsuit) alleging that the Work or a Contribution incorporated within the Work constitutes direct or contributory patent infringement, then any patent licenses granted to You under this License for that Work shall terminate as of the date such litigation is filed. 4. Redistribution. You may reproduce and distribute copies of the Work or Derivative Works thereof in any medium, with or without modifications, and in Source or Object form, provided that You meet the following conditions: (a) You must give any other recipients of the Work or Derivative Works a copy of this License; and (b) You must cause any modified files to carry prominent notices stating that You changed the files; and (c) You must retain, in the Source form of any Derivative Works that You distribute, all copyright, patent, trademark, and attribution notices from the Source form of the Work, excluding those notices that do not pertain to any part of the Derivative Works; and (d) If the Work includes a "NOTICE" text file as part of its distribution, then any Derivative Works that You distribute must include a readable copy of the attribution notices contained within such NOTICE file, excluding any notices that do not pertain to any part of the Derivative Works, in at least one of the following places: within a NOTICE text file distributed as part of the Derivative Works; within the Source form or documentation, if provided along with the Derivative Works; or, within a display generated by the Derivative Works, if and wherever such third-party notices normally appear. The contents of the NOTICE file are for informational purposes only and do not modify the License. You may add Your own attribution notices within Derivative Works that You distribute, alongside or as an addendum to the NOTICE text from the Work, provided that such additional attribution notices cannot be construed as modifying the License. You may add Your own copyright statement to Your modifications and may provide additional or different license terms and conditions for use, reproduction, or distribution of Your modifications, or for any such Derivative Works as a whole, provided Your use, reproduction, and distribution of the Work otherwise complies with the conditions stated in this License. 5. Submission of Contributions. Unless You explicitly state otherwise, any Contribution intentionally submitted for inclusion in the Work by You to the Licensor shall be under the terms and conditions of this License, without any additional terms or conditions. Notwithstanding the above, nothing herein shall supersede or modify the terms of any separate license agreement you may have executed with Licensor regarding such Contributions. 6. Trademarks. This License does not grant permission to use the trade names, trademarks, service marks, or product names of the Licensor, except as required for reasonable and customary use in describing the origin of the Work and reproducing the content of the NOTICE file. 7. Disclaimer of Warranty. Unless required by applicable law or agreed to in writing, Licensor provides the Work (and each Contributor provides its Contributions) on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied, including, without limitation, any warranties or conditions of TITLE, NON-INFRINGEMENT, MERCHANTABILITY, or FITNESS FOR A PARTICULAR PURPOSE. You are solely responsible for determining the appropriateness of using or redistributing the Work and assume any risks associated with Your exercise of permissions under this License. 8. Limitation of Liability. In no event and under no legal theory, whether in tort (including negligence), contract, or otherwise, unless required by applicable law (such as deliberate and grossly negligent acts) or agreed to in writing, shall any Contributor be liable to You for damages, including any direct, indirect, special, incidental, or consequential damages of any character arising as a result of this License or out of the use or inability to use the Work (including but not limited to damages for loss of goodwill, work stoppage, computer failure or malfunction, or any and all other commercial damages or losses), even if such Contributor has been advised of the possibility of such damages. 9. Accepting Warranty or Additional Liability. While redistributing the Work or Derivative Works thereof, You may choose to offer, and charge a fee for, acceptance of support, warranty, indemnity, or other liability obligations and/or rights consistent with this License. However, in accepting such obligations, You may act only on Your own behalf and on Your sole responsibility, not on behalf of any other Contributor, and only if You agree to indemnify, defend, and hold each Contributor harmless for any liability incurred by, or claims asserted against, such Contributor by reason of your accepting any such warranty or additional liability. END OF TERMS AND CONDITIONS APPENDIX: How to apply the Apache License to your work. To apply the Apache License to your work, attach the following boilerplate notice, with the fields enclosed by brackets "[]" replaced with your own identifying information. (Don't include the brackets!) The text should be enclosed in the appropriate comment syntax for the file format. Please do not remove or change the license header comment from a contributed file except when necessary. Copyright 2026 mukul975 Licensed under the Apache License, Version 2.0 (the "License"); you may not use this file except in compliance with the License. You may obtain a copy of the License at http://www.apache.org/licenses/LICENSE-2.0 Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License. # Dave AI resource metadata Creator / publisher: costrict-plugins-repo Original project: https://github.com/costrict-plugins-repo/mukul975-anthropic-cybersecurity-skills-cybersecurity-skills/blob/1b344d155f00bae5cf27d8eba9508e8f5050d904/skills/performing-network-forensics-with-wireshark/SKILL.md Attribution basis: Source repository record Fields of work: Data & Analytics, Development & Engineering Roles: Data Analyst, Security Engineer Specialties: API, Testing Tools: Tshark, Wireshark Country applicability: Country not specified Classification basis: Source catalog labels Instruction SHA-256: db0c2727c827279c22b94bb4e3d3aea18a0c02e2d1cb4324c635fdb2a45a00a9