Plugins are automatically picked up by Firefox as outlined in the How To Stop Automatic Plugin Installations In Firefox. This basically means that the plugin will be added to the web browser if the installation puts it into a directory or location that Firefox scans during startup to find plugins.

Removing the Java Deployment Toolkit

Lets begin with a description of what the Java Deployment Toolkit does:

The Java Deployment Toolkit takes the guess work out of determining what versions of the Java Platform end users have installed on their PCs. It supplies Java based web applet/application deployers with a simple JavaScript interface. This greatly increases the ease of detections of users’ Java environment, as well as the ease of Java Platform deployment.

A plugin that not many Firefox users are likely to need.

We start the removal process by entering about:config in the Firefox address bar. Filter for the term plugin.expose_full_path and set it to true. This will display the full path of each plugin in the about:plugins window that we open afterwards. Double-click the entry to set it to true.

Now open about:plugins the same way. The screen lists the filenames of all plugins that are installed in the Firefox web browser, in this case it is npdeployJava1.dll linked to the Java Deployment Toolkit 6.0.200.2 and npdeploytk.dll linked to the Java Deployment Toolkit 6.0.190.4.

The Java Deployment Toolkit files are located in C:\Program Files (x86)\Mozilla Firefox\plugins\npdeployJava1.dll and C:\Program Files (x86)\Java\jre6\bin\new_plugin\npdeploytk.dll. Users of 32-bit editions of Windows need to remove the (x86) part of the url so that they end up with C:\Program Files\Mozilla Firefox\plugins\npdeployJava1.dll and C:\Program Files\Java\jre6\bin\new_plugin\npdeploytk.dll.

It is now time to close the Firefox web browser and open the plugin locations in Windows Explorer. The plugins can simply be deleted in their folders which will also remove them from running as plugins in the Firefox web browser. Cautious users might want to back up the files first before they remove or delete them from the directories.

The Windows Presentation Foundation Plugin gets installed when the Microsoft .net Framework 3.5 SP1 gets installed in the Windows operating system. Users who noticed the installation also noticed that they were not able to uninstall the plugin, only disable it in the Firefox plugin manager.

Mozilla today blacklisted the Windows Presentation Foundation Plugin. Not because of the silent install but because of a security vulnerability, or to be precise a remote code execution vulnerability. The vulnerability was reported on October 16 and measures to block the plugin were initiated today. Interested users can read up on the vulnerability at the Bug listing at the Mozilla website.

This raises several interesting questions. Could Microsoft be held accountable if computer systems are successfully attacked? Microsoft is not the only developer that is adding plugins to Firefox without asking the user. The Mozilla developers should consider implementing a security control to block unwanted plugins from being installed. Users who have not received the message in Firefox yet should check in the plugin section if the plugin is installed and if it is enabled or disabled. It should be disabled immediately if it is not already.