Ads is one thing but redirecting me to a unknown, potentially malicious site without my permission? That does it. I won't come to Gelbooru ever again.

As far as I know, the site does not do this.

Check for extensions and plugins and run a harddrive scan for malware anyway just in case. Even if you are leaving.

I've gotten extensions that placed invalid ads on Gelbooru's front page, and only the front page... which is supposed to have none, so I know there are adware that will target a specific site's interface.

The only site that does it is Gelbooru. It happened the second I clicked the image for the first time today. I thought it might be an infenction but I have no suspicious addons and Malwarebytes came up empty.
But when I removed Gelbooru cookies and clicked the image it happened again, Two Times!

Just one image?

Nothing is happening to me anywhere.

Not sure if possible, but its probably a good idea to post link if you happened to have that saved. Someone who really matters can look at it.

Back when I used 4chan a lot, I learned that there were innocent image files that could also hold malicious scripts in them. The site would have to find ways to just block people from uploading those pictures at all.

Nope the first random image I click after cookie clean does it for me, afterwards I can surf no problem.
This is the image of the site I'm being redirected to
imgur.com/bXrpHAZ
One more thing, I had Gelbooru unblocked in NoScript. When I blocked it the redirecting stopped. When unblocked it I was instantly redirected.

I can confirm this is happening, so

ugh, so site has been hacked? It's not happening to me so maybe you two got the same adware

Its not hacked, the reason hes being redirected is most likely duo to 3rd party applications such as adblock and noscript or something blocking cookies. Turn your adblocker off, there should be only 1 popunder and its not going to redirect you.

I've been getting malicious re-directs too; it's only been happening on mobile though.

Try turning off the Pop-Under in your settings. Maybe this will stop the redirects. If you still get redirected, it's likely you have adware.