Edit: maybe it was core js. I don't remember the name exactly.
Standard JS. It's a library maintained by one guy in Russia who went to jail for some car accident (I don't have the full context). He needed money and had trouble getting it. Then the Ukraine invasion happened and that only made it more difficult for him to get money. Also he was harassed by less technical people seeing his code on websites thinking it was malicious.
It's really a sad story to me.