Extension_Protected (malware) has been blocked for your protection.

Why was it blocked?
This extension is malware that attempts to make it impossible for a second extension and itself to be disabled, and also forces the new tab page to have a specific URL.
Who is affected?
All Firefox users who have this extension installed.
What does this mean?

The problematic add-on or plugin will be automatically disabled and no longer usable.

When Mozilla becomes aware of add-ons, plugins, or other third-party software that seriously compromises Firefox security, stability, or performance and meets certain criteria, the software may be blocked from general use. For more information, please read this support article.