Alrighty.. I did some more digging and it seems that the latest windows defender update brought a false-positive entry along with it. Lots of other games and software appear to be detected the same way:
https://www.reddit.com/r/StableDiffusion/comments/11vtmyn/windows_defender_threa...
https://github.com/invoke-ai/InvokeAI/issues/2989
I'll look into building 0.50.0 again, resulting in a different zip file, that's hopefully not detected as a false positive? I also checked 0.51 and 0.52, they're both not detected, so I'm pretty confident that we didn't get struck with malicious code injection or something like that.