Something is adding nonsense into my Firefox options menu

[Zlobhater111]

In Firefox's Options menu there will be an Exceptions list. For example Firefox will show a pop-up of a certain website if the URL is added to the Exceptions list of the pop-up blocker. But I checked there are tons of links that I think are malicious websites and the status is set to "Block".

I don't know what added these entries and I removed all of them and re-added one legitimate website that shows updated tropical cyclone information via pop-ups that was overwritten. I scanned using both Spybot S&D and SuperAntiSpyware but it only detected tracking cookies.

I tested my computer for Vundo using some tips from http://bbayles.googlepages.com/antivundo.html and I found no suspicious DLL files and I think my AVG+Avast+Adaware+Spybot Search and Destroy+SUPERAntiSpyware combo removed all of it. I think something else is causing this.

And If it's malware adding these, it also adds lines so Firefox block images of these assumed malicious websites.

Can you please help?