This trophy is unlocked on Claptrap's quest "Claptocurrency" which is acquired in the Dahl Abandon. Follow the quest into "The Veiny Shaft" and once you have the objective to "mine BECHO wafers," the Dark Web will spawn by a cluster of them in the south east of the map. Simply kill it and the trophy will unlock and you don't need to finish the quest if you don't want to.