The keylogger will work on the basis of a script that disables the Firefox browser to ask the user to save his password whenever he logins to a website.
Thereby, allowing the Firefox to store his username and password combination automatically without prompting the user. Just follow these steps to convert your firefox into a keylogger : 1. First and foremost, download the script from here.
2. If you are a Windows user, then navigate to C:/Program Files/Mozilla Firefox/Components
and if you are using MAC, then navigate to Applications -> Right Click Firefox -> Show Package Contents -> Contents/MacOS/Components
3. In the downloaded rar file, you will find a script named as nsLoginManagerPrompter.js, simply extract and then copy and paste the file in the folder that is applicable to you.
That's It