[Scoundreller]

Is there a Google option to perma-ban a domain?

Maybe a place I can upload a HOSTS file?

Or an extension that adds this to every search?

[9dev]

There is: uBlacklist[1]. I've been searching for the exact same thing to get rid of Indian tutorial scamsites, bad GitHub and StackOverflow clones and, of course, Pinterest results :) Can recommend.

[1] https://chrome.google.com/webstore/detail/ublacklist/pncfbmi...

[Laforet]

You can try this extension. It was forked from a project once maintained and abandoned by Google themselves.

https://chrome.google.com/webstore/detail/personal-blocklist...

https://addons.mozilla.org/en-US/firefox/addon/personal-bloc...