Mozilla Safe Browsing and others (Medfos malware) has been blocked for your protection.

Why was it blocked?
This block covers a number of malicious add-ons that deceive users, using names like "Mozilla Safe Browsing" and "Translate This!", and claiming they are developed by "Mozilla Corp.". They hijack searches and redirects users to pages they didn't intend to go to. Note: this block won't be active until bug 799266 is fixed.
Who is affected?
All Firefox users who have installed any of these add-ons.
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.