"Ads not by this site" Malware?

[Teleportable]

Hi!

Looks like I may have accidentally downloaded something I shouldn't have on my Macbook. When running Firefox I get annoying banners that pop-up on pages that shouldn't have ads (image links included). The ads are always promoting something different, but below the banners there is text that reads, "Ads not by this site." Anyone know what the problem might be and how I can fix it?

So far, I'm only having the issue when using Firefox.

I'm running OS X 10.6.8 and using Firefox 18.0.1.

https://www.dropbox.com/s/h4lwl4r45q3usb5/Screen shot 2013-01-25 at 1.17.27 AM.jpg

https://www.dropbox.com/s/bz411wy1few1d46/Screen shot 2013-01-25 at 1.17.55 AM.png

https://www.dropbox.com/s/m8cjewpztiia3pa/Screen shot 2013-01-25 at 1.27.42 AM.png

Any guidance would be so appreciated!

 

[Quad5Ny]

It's probably just a Firefox plugin or add-on. The quickest way would be to uninstall Firefox completely and then re-install it.

Make sure to backup any bookmarks, ect..

http://kb.mozillazine.org/Uninstalling_firefox#On_Mac_OS_X

 

[Teleportable]

It's probably just a Firefox plugin or add-on. The quickest way would be to uninstall Firefox completely and then re-install it.

Make sure to backup any bookmarks, ect..

http://kb.mozillazine.org/Uninstalling_firefox#On_Mac_OS_X

That seems to have worked! Woohoo! Thank you SOOOOO much!!!!