Google Roguekiller, download it and run it, might pick up some nasty stuff regardless if you reinstalled windows. As for password requests; add 2-step authentication to your email / Runescape if you don't already. Temporarily stick to using a different device to change your passwords. As far as I know you can't send & execute a file through teamviewer at least instantly, you would of seen him try and that process takes a while.