We do use "Troll" and "trollen" in German forums. But is there another Word that predates the Internet that could be used instead?
According to the Wikipedia article, troll originates from the French verb trôler, but also from the Norse word troll.
Let's concentrate on the second one here. A troll is a mythological monster. The German word for Troll is Troll, so there is no difference.
As for the activity of trolling: This is an artificial word created for this purpose, so there is no direct translation we can use. However, trolling means something like ködern (as you can read here). So I would go for that.