Virulence Location?

I have been searching long and hard for this skill, it would go perfect for my build. But I can't find it!! I have searched websites for its location and everyone says that it is in the Frozen Forest from a boss called Unthet Rotwood. But, I have searched the Frozen Forest ten times over and still no luck. I found about 3 other Pinesoul bosse there, but none had this skill. If anyone can help me out or maybe post a pic of a map with that boss's location that would be great. I also heard that there was a boss in Ettin's back that had it, but I think that was taken out of the game. Thanks for the help!

I know in recent patches they have changed monster spawning points (i have also been looking for an Elite from Frozen Forest - Defy Pain) and with my elite I can't find the boss either. The only think i can think of is that they A) changed the creature so that he doesnt spawn or B) they moved the elite to another area.