hi, this is adware/malware which has nothing to do with firefox. please perform all these steps:

1. reset firefox (this will keep your bookmarks and passwords)
2. afterwards go to the firefox menu ≡ > addons > extensions and in case there are still extensions listed there, disable them.
3. finally run a full scan of your system with different security tools like the free version of malwarebytes and adwcleaner to make sure that adware isn't present in other places of your system as well.

Troubleshoot Firefox issues caused by malware

ok, i deleted this folder C:\Program Files (x86)\RelevantKnowledge\ killing the process Relevant-Knowledge if needed.

ee comes from tmrginc.com market research. perhaps this prog comes with SUMo-Updater, the only prog i installed recently.

thanks :)

and AdwCleaner finds RelevantKnowledge background system services too! :D Very usefull :)

AdwCleaner asks after cleaning to restart and close all progs/apps after an ok. Has to be after deleting services. And it runs without installing :)

pisspott said

perhaps this prog comes with SUMo-Updater, the only prog i installed recently.

Where do you see the name SUMo-Updater? That could be a third party bundle updater.

SUMo is Software Update Monitor and only the lite version comes without "sponsor.exe": http://kcsoftwares.com/?sumo