Sharing A PCAP With Decrypted HTTPS
How to Share a PCAP with Decrypted HTTPS: A Practical Guide for Network Analysts
If you are a network analyst who deals with suspicious or malicious network traffic, you may have encountered the challenge of decrypting HTTPS traffic from a PCAP file. HTTPS is a protocol that encrypts the data exchanged between web browsers and servers, making it difficult to see the details of the HTTP requests and responses. This can hinder your ability to identify and analyze the behavior of malware or botnets that use HTTPS to communicate with their command and control (C2) servers or to exfiltrate data.
Sharing a PCAP with Decrypted HTTPS
In this article, we will show you how to decrypt HTTPS traffic from a PCAP file using Wireshark, a popular network analysis tool. We will also explain how to share a PCAP with decrypted HTTPS with other analysts or researchers, while minimizing the risks of exposing sensitive or personal information. By following this guide, you will be able to decrypt HTTPS traffic from a PCAP file and share it with others in a secure and efficient way.
What do you need to decrypt HTTPS traffic from a PCAP file?
To decrypt HTTPS traffic from a PCAP file, you need two things: Wireshark and an encryption key log file. Wireshark is a software that allows you to capture, view, filter, and analyze network traffic. You can download Wireshark for free from https://www.wireshark.org/. An encryption key log file is a text file that contains the encryption keys used for each TLS session in your PCAP file.
TLS stands for Transport Layer Security, and it is the protocol that provides encryption and authentication for HTTPS traffic. TLS uses encryption keys to encrypt and decrypt the data for each session. These keys are generated during a process called TLS handshake, where the browser and the server agree on a set of cryptographic parameters.
An encryption key log file can be generated by your browser or by a proxy tool that intercepts and decrypts your HTTPS traffic. For example, if you use Firefox or Chrome as your browser, you can set an environment variable called SSLKEYLOGFILE to point to a file where your browser will store the encryption keys for each TLS session. Alternatively, you can use a proxy tool like PolarProxy or mitmproxy to intercept and decrypt your HTTPS traffic and generate an encryption key log file.
How to use Wireshark to decrypt HTTPS traffic from a PCAP file?
Once you have your PCAP file and your encryption key log file, you can use Wireshark to decrypt HTTPS traffic from your PCAP file. Here are the steps to do so:
Open Wireshark and go to Edit > Preferences > Protocols > TLS.
Under (Pre)-Master-Secret log filename, browse to your encryption key log file.
Click OK to save your preferences.
Open your PCAP file in Wireshark.
You should see decrypted HTTPS traffic in Wireshark's packet list pane. You can also follow TCP streams or HTTP streams to see the decrypted HTTP messages in plain text.
By decrypting HTTPS traffic from your PCAP file, you will be able to see the details of the HTTP requests and responses, such as the URLs, headers, cookies, or body content. This will help you identify and analyze the behavior of malware or botnets that use HTTPS to communicate with their C2 servers or to exfiltrate data.
How to share a PCAP with decrypted HTTPS?
If you want to share a PCAP with decrypted HTTPS with other analysts or researchers, you need to make sure that they have access to both your PCAP file and your encryption key log file. You also need to make sure that they use Wireshark version 3.x or later, which supports TLS decryption using encryption key log files.
You can share your PCAP file and your encryption key log file using any secure method of your choice, such as email attachments, cloud storage services, or encrypted messaging apps. However, you should be aware of some potential risks when sharing these files:
Your PCAP file may contain sensitive or personal information that you do not want to disclose to others. For example, your PCAP file may reveal your browsing history, online accounts, passwords, credit card numbers, or other confidential data.
Your encryption key log file may allow others to decrypt other HTTPS traffic that uses the same keys as your PCAP file. For example, if you use Firefox or Chrome as your browser and generate an encryption key log file for all your TLS sessions, anyone who has access to that file can decrypt any HTTPS traffic from your browser.
To mitigate these risks, you should consider doing some of the following:
Filter out any irrelevant or sensitive traffic from your PCAP file before sharing it. For example, you can use Wireshark's display filters or export filters to only include traffic related to your analysis topic.
Use a proxy tool that only intercepts and decrypts specific HTTPS traffic that you are interested in analyzing. For example, you can use PolarProxy or mitmproxy to only intercept and decrypt HTTPS traffic from certain domains or IP addresses.
Delete or overwrite your encryption key log file after sharing it or after completing your analysis. For example, you can use a secure deletion tool like Eraser or shred to permanently erase your encryption key log file from your disk.
Conclusion
In this article, we have shown you how to decrypt HTTPS traffic from a PCAP file using Wireshark and an encryption key log file. We have also explained how to share a PCAP with decrypted HTTPS with other analysts or researchers in a secure and efficient way. By following this guide, you will be able to decrypt HTTPS traffic from a PCAP file and share it with others for further analysis.
How to use PolarProxy to intercept and decrypt HTTPS traffic?
If you do not want to use your browser to generate an encryption key log file, or if you want to intercept and decrypt HTTPS traffic from other devices or applications, you can use a proxy tool like PolarProxy. PolarProxy is a transparent TLS proxy that can intercept and decrypt HTTPS traffic and generate an encryption key log file. You can also use PolarProxy to stream decrypted HTTPS traffic to Wireshark or NetworkMiner using PCAP-over-IP.
PolarProxy can run on Windows, Linux, or macOS, and it can be configured as a WiFi access point, a router, or a proxy server. You can download PolarProxy for free from https://www.netresec.com/?page=PolarProxy. To use PolarProxy to intercept and decrypt HTTPS traffic, you need to do the following:
Install PolarProxy on your machine and start it with the appropriate options. For example, you can use the following command to start PolarProxy with PCAP-over-IP enabled on TCP port 57012 and encryption key log file output enabled:
polarproxy.exe --pcapoverip 57012 --certhttps 10443 --certlog keys.log
Configure your device or application to use PolarProxy as a proxy for HTTPS traffic. For example, you can connect your device to the WiFi access point created by PolarProxy, or you can set your application's proxy settings to point to PolarProxy's IP address and port.
Generate HTTPS traffic from your device or application. For example, you can visit a website that uses HTTPS, or you can run a malware sample that uses HTTPS for C2 communication.
PolarProxy will intercept and decrypt HTTPS traffic and store the encryption keys in the encryption key log file. You can also connect Wireshark or NetworkMiner to TCP port 57012 on PolarProxy's machine and stream decrypted HTTPS traffic in real time.
By using PolarProxy to intercept and decrypt HTTPS traffic, you will be able to capture HTTPS traffic from any device or application and generate an encryption key log file for Wireshark decryption. You will also be able to stream decrypted HTTPS traffic to Wireshark or NetworkMiner for live analysis.
Conclusion
In this article, we have shown you how to decrypt HTTPS traffic from a PCAP file using Wireshark and an encryption key log file. We have also explained how to share a PCAP with decrypted HTTPS with other analysts or researchers in a secure and efficient way. Additionally, we have introduced PolarProxy as an alternative tool for intercepting and decrypting HTTPS traffic and generating an encryption key log file.
We hope that this article has helped you understand how to decrypt HTTPS traffic from a PCAP file and share it with others for further analysis.
How to use mitmproxy to intercept and decrypt HTTPS traffic?
Another proxy tool that you can use to intercept and decrypt HTTPS traffic is mitmproxy. mitmproxy is an interactive TLS proxy that can intercept and modify HTTPS traffic on the fly. You can also use mitmproxy to generate an encryption key log file or to export decrypted HTTPS traffic as a PCAP file.
mitmproxy can run on Windows, Linux, or macOS, and it can be configured as a transparent proxy, a reverse proxy, or a SOCKS proxy. You can download mitmproxy for free from https://mitmproxy.org/. To use mitmproxy to intercept and decrypt HTTPS traffic, you need to do the following:
Install mitmproxy on your machine and start it with the appropriate options. For example, you can use the following command to start mitmproxy with encryption key log file output enabled:
mitmproxy --set ssl_keylogfile=keys.log
Configure your device or application to use mitmproxy as a proxy for HTTPS traffic. For example, you can connect your device to the same network as mitmproxy and set its proxy settings to point to mitmproxy's IP address and port.
Generate HTTPS traffic from your device or application. For example, you can visit a website that uses HTTPS, or you can run a malware sample that uses HTTPS for C2 communication.
mitmproxy will intercept and decrypt HTTPS traffic and store the encryption keys in the encryption key log file. You can also use mitmproxy's console interface or web interface to view and modify decrypted HTTPS traffic on the fly.
If you want to export decrypted HTTPS traffic as a PCAP file, you can use mitmproxy's export feature. For example, you can press "E" in the console interface or click on "Export" in the web interface and select "Raw TCP" as the export format.
By using mitmproxy to intercept and decrypt HTTPS traffic, you will be able to capture HTTPS traffic from any device or application and generate an encryption key log file or a PCAP file for Wireshark decryption. You will also be able to view and modify decrypted HTTPS traffic on the fly using mitmproxy's interactive interface.
Conclusion
In this article, we have shown you how to decrypt HTTPS traffic from a PCAP file using Wireshark and an encryption key log file. We have also explained how to share a PCAP with decrypted HTTPS with other analysts or researchers in a secure and efficient way. Additionally, we have introduced PolarProxy and mitmproxy as alternative tools for intercepting and decrypting HTTPS traffic and generating an encryption key log file or a PCAP file.
We hope that this article has helped you understand how to decrypt HTTPS traffic from a PCAP file and share it with others for further analysis.
Conclusion
In this article, we have shown you how to decrypt HTTPS traffic from a PCAP file using Wireshark and an encryption key log file. We have also explained how to share a PCAP with decrypted HTTPS with other analysts or researchers in a secure and efficient way. Additionally, we have introduced PolarProxy and mitmproxy as alternative tools for intercepting and decrypting HTTPS traffic and generating an encryption key log file or a PCAP file.
By following this guide, you will be able to decrypt HTTPS traffic from a PCAP file and share it with others for further analysis. You will also be able to use different proxy tools to intercept and decrypt HTTPS traffic from any device or application. This will help you improve your network analysis skills and gain more insights into malicious or suspicious HTTPS traffic.
We hope that this article has been useful and informative for you. If you have any questions or feedback, please feel free to leave a comment below. 6c859133af