Trojan from "Brave beta" version! [Trojan:Script/Conteban.A!ml]

I’m using a new PC, new Windows 11, nothing more than Brave as downloaded browser. I just was playing some music on YouTube while reading a book, so Windows Security found it and deleted it as well, but hasn’t to be with what you’re saying. Anyway, it was deleted as soon as possible and that’s why I was wondering, if just downloaded Brave Beta, why do I will see that coming?. Btw, Microsoft Safety Scanner didn’t found nothing after Windows Security deleted it. We’re inside Internet after all, just wonder that this was detected from Brave and never since years that happened to me.