99% of computers w/ a sound card have a gameport... so you probably have one... now as to why it all of a sudden recognized it, your guess is as good as mine... the only thing i can think of is that it was removed from the device manager then it found it the next time you booted...
i don't believe you were hacked...
did you (or someone else) mess w/ any drivers the previous time you had the computer on?
Josh