Looking for Gametype (Infection variant)

I’m looking for a gametype and map that was on Sandbox. One player would spawn with a sniper on the middle level of Sandbox and all others would be in the lowest level underground. When the players on the lowest level spawned they had flamethrowers but could drop them and then have no weapon. All around these players on the lowest floor were dummy spartans, looking exactly like the real players. The goal was for the person with the sniper to find and kill the real players in a certain amount of time.

If anyone knows the gametype that I speak of please reply. Yes I do think that it’s modded, but it’s not a bad mod against the spirit of the game.

Also, for anyone wanting good infection gametypes, I’ve put a lot into an account’s file share: GT: Mrs Koenen.