JJ vs suspected donk

It's early, so I don't know much about the villain, but I suspect he's very loose.

$2/$4 No Limit Holdem
5 players
Converted at weaktight.com

Profiles and Stacks:
UTG ($358.76) 33.3/16.7/3.0 (6)
CO ($910.20) 60.0/33.3/1.5 (15)
Hero ($546.00) 33.3/13.3/4.0 (15)
SB ($494.90) 33.3/20.0/3.0 (15)
BB ($67.68) 46.7/6.7/2.0 (15)

Pre-flop: ($6, 5 players) Hero is BTN
1 fold, CO raises to $8, Hero raises to $24, 2 folds, CO raises to $100, $76 to Hero ($522)?

i would just fold if you don't know anything, and i would hate to call and see anything but a jack.