Villain is unknown.

PokerStars No-Limit Hold'em, $0.50 BB (8 handed) Poker-Stars Converter Tool from FlopTurnRiver.com (Format: FlopTurnRiver)

UTG+1 ($52.75)
MP1 ($48.45)
MP2 ($75.10)
Hero ($50.50)
Button ($56.25)
SB ($50.25)
BB ($45.85)
UTG ($86)

Preflop: Hero is CO with K, A.
UTG raises to $1.5, 3 folds, Hero calls $1.50, 3 folds.

Flop: ($3.75) T, K, 8 (2 players)
UTG bets $3.5, Hero calls $3.50.

Turn: ($10.75) 8 (2 players)
UTG checks, Hero bets $6.5, UTG calls $6.50.

River: ($23.75) A (2 players)
UTG bets $22, Hero ...