Last Chaos

<?php$ik_id="FEB656D1-CF1C-C4A0-75B7-9D8CBB5D8069";$sk_ik="qrZkEr5vJItyaKux";$sing_hash_str = $ik_id.':'.$_POST['ik_payment_amount'].':'.$_POST['ik_payment_id'].':'.$_POST['ik_paysystem_alias'].':'.$_POST['ik_baggage_fields'].':'.$_POST['ik_payment_state'].':'.$_POST['ik_trans_id'].':'.$_POST['ik_currency_exch'].':'.$_POST['ik_fees_payer'].':'.$sk_ik;$sign_hash = strtoupper(md5($sing_hash_str));if($_POST['ik_sign_hash']==$sign_hash){$cash=$_POST['ik_payment_amount'];$login=$_POST['ik_payment_id'];$ip ="127.0.0.1";$sqluser ="root";$sqlpw ="";$userdb ="newproject_db_auth";$conn =new mysqli($ip,$sqluser,$sqlpw,$userdb);$insertusr ="UPDATE bg_user SET cash = cash + '$cash' *5 WHERE user_id = '$login'";       $qInsert = $conn->prepare ($insertusr);       $qInsert->execute();#