Pretty certain. Unless Vortex pushes said sanity checks through it's official notification system as a Vortex update. It was the green notification in the notifications dropdown which tells you a (presumably) official update is available. I even waited a week or two between when I first saw it and when I decided to click it. Modding some games can get delicate and when things are working I don't like to screw anything up. After I clicked it, it went straight into a Windows update. One which Windows Update said did not happen. There is no mistaking that screen, though. You can't do anything else while it is running. The AMD update runs differently and prompts you to restart from the desktop after the download has finished.
I've also received several system runtime type errors, "blue screen of death".. resetting the drivers does not seem to have fully solved the issue.
It's extremely puzzling and troubling. The only thing that makes sense to me is that a malicious update was allowed to be pushed through somehow.
I could be wrong, sure. I just don't see how. Also, Vortex completely nuking itself as a result is completely baffling in it's own right. I didn't grab anything from offsite whatsoever. I was updating the app, not a mod or anything.. it just doesn't seem realistic whatsoever that anything else could be responsible.