On a separate issue, if you are running manual updates on your Windows, update now. There were some security flaws fixed in the latest update released yesterday.
Regarding the topic, a bug has been announced (not yet fixed) that can be used to attack a computer that has Firefox installed.
The ironic thing is that this attack on Firefox is only done through IE. IE will allow you to click on a carefully crafted link that will then open Firefox while executing other malicious code in the process. Clicking the same link within Firefox does nothing.
Microsoft is refusing to address the issue because if you don't have Firefox installed (as far as they know right now) this will not do any damage. So, they are basically saying that because it does not effect any Microsoft software, it is ok to leave the hole open.
The Mozilla (Firefox) team says they will fix the flaw in the way that this is allowing Firefox to launch and put out the update.
The question that is being argued is if this is an IE problem for having the hole that allows this through, or a Firefox problem for the way it allows the program to be loaded.
I think IE should close the hole before someone figures out another way to use it to attack machines, AND Firefox should fix their hole before someone else figures out another way to exploit it.
This is exactly what makes me so mad at Microsoft. They are basically saying "Yes, there is a hole in our browser, but that will teach you for downloading Firefox . . . so there . . . HA! HA!"