Talk:Hellfire/@comment-28911476-20160831063550/@comment-27279105-20160831065301

under "dropped by" it says "Infested T3 Defense Reward". that means you need a defense mission where the faction is infested and the level range is 30+.

on the Defense page you can find a list of defense missions. the only defense mission from that list that fits those requirements is Eris, Kala-aza on rotation C.

it could be much easier to farm Ambulas though, he also drops the mod. this boss is quite easy and the mission can be done in 1-2min with appropriate gear. happy farming!