Malfeasance can be obtained by finishing its exotic quest, which requires the following:
Play Gambit matches until an Ascendant Primeval spawns instead of a normal one. The round in which the Ascendant Primeval spawns must be won in order for it to drop The Seething Heart, which is required to continue the next steps.
Once you receive The Seething Heart, return to the Drifter, where he will grant the quest step City of Secrets.
Travel to the Dreaming City and defeat 25 Taken bosses or minibosses (enemies with yellow health bars).
The next step of the quest requires completing a special variant of The Corruptedstrike. Follow the markers to Callum's Grave. You'll receive a Depleted Weapon Core.
Return to the Drifter and receive the quest step, Business as Usual.
Play Gambit matches and earn points by banking Motes and winning matches. Note that if you drop or lose any Motes during a match, you'll lose progress and there's a x2 loss penalty for each Mote lost. Fill both bars up to 100% to unlock the final step, Lights Out.
Defeat 25 opposing Guardians in Gambit, by either invading the other team or killing invaders. Also kills 4 Guardians in one invasion or have a teammate do it for you 3 times.[1][2]
