Claptrap offers you a mission called "Claptocurrency." Once you enter "The Veiny Shaft" you will be run into some spiderants. In the south-east portion of the exploration area, The Dark Web will spawn.
The achievement popped right after I killed it.
The mission can be found in the Dahl Abandon - thank you Advena
This achievement is missable if you mine the last crystal before killing the Dark Web - Thank you alpaca777
Multiple people are saying that the achievement is not popping until they reload their profiles to their Xbox.