Take a default Genesis 8 Female character, do nothing with her, but resave her as a scene or scene subset.
Then back up ALL FILES inside of "\Documents\DAZ 3D\Studio\My Library\data\DAZ 3D\Genesis 8\Female\Morphs".
Then delete them all (making certain you have your backup of them available, mine is on a separate drive).
Reload Daz3D up and load up your default G8F scene and take note of missing morphs it reports. They are most likely parasite morphs you can permanently remove. Any that are needed for other characters I will add back in from my backup as needed.
The following morphs are morphs I removed which were parasite morphs. I keep a list of them I can refer to in the future if I get an older character I load and it reports one of these missing, than I can resave the character without them.
Morphs to ignore and remove
/data/DAZ 3D/Genesis 8/Female/Morphs/RFem/Ana B9/Analeine.dsf
/data/DAZ 3D/Genesis 8/Female/Morphs/xenic101/Musculature/Flex/xFLXCollarUpR.dsf
/data/DAZ 3D/Genesis 8/Female/Morphs/xenic101/Musculature/FlexAlt/xFLXAltCollarUpR.dsf
/data/DAZ 3D/Genesis 8/Female/Morphs/Zev0/Breast Control/Nipples Size.dsf
/data/Daz 3D/Genesis 8/Female/Morphs/Marcius/Leia/LeiaEyeFixLeft.dsf
/data/Daz 3D/Genesis 8/Female/Morphs/Marcius/Leia/LeiaEyeFixRight.dsf
/data/Daz 3D/Genesis 8/Female/Morphs/zoro_d/Kitten/Genitalia/!Tight Vagina.dsf
Parasite Genesis 8 Male Morphs
...Alistair is REALLY bad! If you load in a new G8M, he will instantly get these morphs applied, so don't install him...
/data/DAZ 3D/Genesis 8/Male/Morphs/PedroFurtadoArts/Alistair/Alistair Body.dsf
/data/DAZ 3D/Genesis 8/Male/Morphs/PedroFurtadoArts/Alistair/Alistair Head.dsf
/data/DAZ 3D/Genesis 8/Male/Morphs/PedroFurtadoArts/Alistair/Alistair.dsf