Previously the villain had played v. passively limping in UTG with QQ and just calling raises on each street from another player, a king had landed on the flop though.

Im not sure how to read the river bet...has he got something here or is this a bluff? My feeling is that because he has played so passively if he had something he would more likely make a weak bet here rather than shove

PokerStars No-Limit Hold'em, $0.05 BB (4 handed) - Poker-Stars Converter Tool from FlopTurnRiver.com

UTG ($8.93)
Button ($5.32)
SB ($8.10)
Hero (BB) ($13.46)

Preflop: Hero is BB with 7, 7
1 fold, Button calls $0.05, SB calls $0.03, Hero raises to $0.25, Button calls $0.20, 1 fold

Flop: ($0.55) 2, 3, 2 (2 players)
Hero bets $0.40, Button calls $0.40

Turn: ($1.35) 8 (2 players)
Hero bets $1.30, Button calls $1.30

River: ($3.95) 5 (2 players)
Hero checks, Button bets $3.37 (All-In), Hero ???