Oberon Media Game Pack was insalled without my permission, how could it happen?

General Topics
1

While removing a program from my PC I noticed, that on 2012-01-04 the Oberon Media Game Pack was installed without my permission, how could it happen?
I never knew before that Oberon Media was existing,at all.
I sure did not search for them.
I had installed the free avast edition at that time .
How can I avoid such unwanted happenings?

Thx, clavast.

2

Oberon Media Game Pack does come preinstalled on many computers so maybe someone has clicked on one of the trial games which has then activated it ???