This extension allows you to run applications based on Microsoft's ClickOnce technology. The extension intercepts the *.application request in the OnBeforeRequest to avoid the built-in Download Manager UI, to launch the ClickOnce app and to redirect the request to javascript:void() to cancel it silently. It is developed with WebExtension (Native Messaging) and all the source code has been provided when the extension was published. It is only available for Windows platform. More information regarding ClickOnce: https://docs.microsoft.com/en-us/visualstudio/deployment/clickonce-security-and-deployment?view=vs-2019 https://en.wikipedia.org/wiki/ClickOnce You can test it with the following url: https://bayden.com/test/clickonce/. It will download a test application that uses this technology (a SmartScreen warning could appears with the ClickOnce executable but that is unrelated to the extension). We have the same extension for Chrome: https://chrome.google.com/webstore/detail/meta4-clickonce-launcher/jkncabbipkgbconhaajbapbhokpbgkdc. Here are two bug thread in Chromium (with additional info): https://crbug.com/941653 and https://crbug.com/936754 There is no obfuscated code, the source code is available and the native executable can be disassembled with ILSpy (https://github.com/icsharpcode/ILSpy)