It is Scribefire. I love the way I can develop my posts while actually on the sites I am researching or that triggered the post. It makes linking, adding images, and getting resource materials a breeze. It also cuts down on the time necessary to create the post.
Scribefire works with many blogging platforms, but, it is only available for Firefox at this time. And yes, there was a Firefox vulnerability that was recently using Scribefire as a vehicle. That has been patched and is no longer and issue. Plus, hackers and bandits are always looking for ways to exploit systems. Get a good defense system, like Avast, and keep it up to date.
Here is a bit more about Scribefire from Mahalo. This gives a lot of information about Scribefire and even has a tutorial.