Weak preflop play leading to a tough decision

I cashed in a freeroll, and then won a satellite to $55 turbo with 1.5 million prize pool. Coming off of two donkfests had my play tailored to navigating erratic players, and I psyched myself out in the early stages of the tourney. This brought me to the following hand.


MP1 (t47,435)
MP2 (t56,770)
MP3 (t53,647)
CO (t45,687)
Hero (Button) (t31,340)
SB (t48,979)
BB (t50,472)
UTG (t47,395)
UTG+1 (t68,275)

Hero's M: 38.69

Preflop: Hero is Button with ,
1 fold, UTG+1 raises to t900, 3 folds, CO calls t900, Hero calls t900, 1 fold, BB raises to t3,300, UTG+1 calls t2,400, CO calls t2,400, Hero calls t2,400

Flop: (t13,710) , , (4 players)
BB checks, UTG+1 checks, CO bets t6,600, Hero calls t6,600, 2 folds

Turn: (t26,910) (2 players)
CO bets t12,900

Having failed to raise appropriately and allowing 4 players cheaply to the flop, it seems to me that Ax, 55, 77 are all strong contenders. Villain is complete unknown, having moved to the table 3 hands prior and not entering a pot. Seems to me that our options are jam or fold.

Which way do you lean, and why?