Not exactly what you’re asking for but uBlacklist is a plugin that lets you blacklist websites from showing in your search results. I’ve only been playing with it for a few days but it seems to work great for Google, DuckDuckGo, and Bing. Qwant is a little wonky.
Lasse Collin is not the perpetrator, that would be “Jia Tan”.
https://tukaani.org/xz-backdoor/