RibShark: Rayman Forever has remnants of an old virus named CIH. These are only remnants, it is enough for antiviruses to pick it up, but the virus code itself is inactive. Not to mention, the virus has no effect on modern Windows systems, so unless you are running Windows 9x it won't harm anything.
That being said, GOG really should replace those EXEs. There are versions that do not have the remnants that are available, and it would probably save them from a lot of support requests.
The system I'm on reports "Trojan:Win32/Zpevdo.B", in Rayman Forever\RayKit\OSD\CLIENT.EXE.download. It and the game folder keep reappearing, even though I cancelled the download in Galaxy.