Halo Infinite

Game mode: Multiplayer - Big Team Battle (This must be done in matchmaking, not customs)
Map: Fragmentation

Location: There are two caves on the left and right side of the map; The cave doors are triangle forerunner doors laced with red to indicate locked and turn blue when unlocked with a collum to the left of the doors. You can better identify them by looking at the door and pressing , the caves are named Rock Vault Courtyard & Hex Vault Courtyard.

Solution: Stand at the column & press and hold the action button to start the hack using your A.I. The hack will take 20 sec to complete so I recommend having a few teammates around as you must remain within 25m for the hack to complete. After the hack the doors will turn from red to blue and open, this is when the achievement pops.

Notes:
1)The door lock has a cooldown of 2 min before it can be hacked again.
2)You do not have to enter the cave just be the one to initiate the hack.

On BTB, in the map fragmentation, there is a red door you can hack with your AI. it can be hard to explain where it is via text, but it's to the left of spawn. here is a video for reference:

On the BTB map Fragmentation, at a location called Hex Vault Courtyard you can find the 'loot cave'. To enter you must go up to a console next to the door, press and hold and your AI will hack the door open. You must remain close to the door while the AI hacks, this only takes a moment.

Once it successfully hacks the door open, you get the achievement.

Inside you'll find a couple of power weapons and a piece of equipment.

To unlock this achievement, start a BIG TEAM BATTLE game. Two Loot Caves can be found on the FRAGMENTATION map. Look for a closed door with a red light and use your AI to hack it. You must stay by your AI until the hack is complete. The door will then open and you will get the achievement. Here is a video guide showing what to do.

While the tried and true method of playing on Fragmentation in Big Team Battle does still work, it can be difficult to get the map in that mode, and you may be competing with other players to open the loot cave (or you may just not prefer to play Big Team Battle)

As of today (2/5/2024), the Cyber Showdown update has added Fragmentation to Firefight. You can load into Firefight on Fragmentation and open the loot cave there as well.

It is worth noting that the cave was locked for me until we had captured a hill in front of the loot cave. (We were playing KOTH Firefight). Your mileage may vary.

To get this Achievement you must open a Loot Cave “door” in a Matchmade game.

This can be done in Big Team Battle “BTB” by playing on the map Fragmentation by going at the edges of the map.

There will be a console that you can use your AI to unlock the door, but you must stay nearby so it can unlock.