Lifting the veil - how to test browsers for spyware
https://digdeeper.club/articles/liftingtheveil.xhtml
Privacy is a key factor when choosing a web browser, but users often rely on assumptions or marketing claims.
Mitmproxy offers a way to test a browser's privacy by monitoring its connections. This tool acts as a local proxy server, allowing users to see all the connections a browser makes, including those made without user input.
Mitmproxy can decrypt SSL traffic by adding a root certificate to the browser, enabling users to inspect all requests and responses. This process involves setting up mitmproxy, configuring the browser to use the proxy, and adding the certificate. Users can then observe the browser's behavior, including unsolicited requests, to assess its privacy practices.
Mitmproxy is particularly useful for identifying spyware in browsers, as it provides a clear view of all outgoing and incoming data. While it has limitations, such as not capturing initial requests made before the proxy is set up, it remains a powerful tool for privacy-conscious users.
For a comprehensive spyware investigation, mitmproxy is recommended over Wireshark due to its simplicity and ability to isolate application traffic.
https://sizeof.cat/post/web-browser-telemetry-2025-edition/