When I was on a bender watching SiIvagunner videos (for those who don't know, it's a channel posting anything from YTPMVs to remixes to actual comedy skits disguised as video game soundtrack rips), I clicked on one from a Spiderman video game. It was like 13 seconds long and there was no music, just a clip of a yellow lit room with the camera facing a mirror and a moderately loud buzzing noise in the background. I didn't get what the 'joke' was supposed to be until I found the full video online later. Turned out to be some guy in a Spiderman mask wanking it on camera.

I know that's kinda lame, but it's hard to recall something that's unintentionally weird. Is that not what OP is looking for? Feels to me like most weird things on the internet are intended to be so.