End of the world? No. But it's really, really bad.
When you get your stolen car back, problem over.
But your broken into system should in most cases be considered forever tainted until fully reinstalled. You can't enumerate badness. That the antivirus got rid of one thing doesn't mean they didn't sneak in something it didn't find. You could be still a DoS node, a CSAM distributor, or a spam sender.