Who said it was fake? I assume that if it was fabricated, it would've been more substantial. But I'm not gullible enough to think Biden's kid's sex tape found its way to the media in October by some sort of wacky accident.
I'm dismissing it because it doesn't seem to contain any evidence of Joe Biden doing anything bad. It seems like someone hacked his kid's email, went through it for embarrassing stuff, didn't find much, and so released it very close to the election because there wasn't enough dirt there to sustain a longer scandal.