Persistence With “Fiddler Classic” Extensions
First a quick definition from the website:
Fiddler Classic and fiddler Everywhere are special-purpose proxy server tools for debugging web traffic from applications like browsers. They’re used to capture and record this web traffic and then forward it onto a web server
Similar to Notepad++ and many other applications out there in that Fiddler also allows the use of plugins to enhance the user’s experience and make the tool more full-featured. It also allows the ability to write a custom plugin/extension by writing a DLL and placing it in the scripts folder.
Here are the steps to create a simple plugin that loads “calc” as a POC (I’m not creative sorry).
- From VStudio create a new project and select “Class Library (.Net Framework).
- Once created we need to add “fiddler.exe” as a reference to the project. For that right-click on reference and browse for the location of the binary.
- Write the following code. (See this for more examples)
4. Compile it and copy it to the “script” folder of a fiddler installation.
5. (Re)start “Fiddler Classic” and notice your beautiful calc.
One thing to note is that the default installation for “Fiddler Classic” is “%localappdata% which is user-controlled :)
That’s it for this quick post, thanks for reading. You can find me on Twitter @nas_bench