Codec extensions (malware) has been blocked for your protection.

Why was it blocked?
The set of extensions labeled as Codec, Codec-M, Codec-C and other names are malware being distributed as genuine add-ons. If you think an add-on you installed was incorrectly blocked and the block dialog pointed you to this page, please comment on this blog post.
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.