Hm, that is odd. I did a quick web search and it looks like there's malware that sometimes goes by the name "Conduit". Microsoft's website has a webpage about it (Link). My best guess is that Defender saw the DLL file named Conduit and flagged it, thinking it was that malware...
This is the first time I've ever heard anything about this. As far as I know, everyone else who has installed the game hasn't had their antivirus warn them. I'm not sure why it was your installation in particular that gave a false positive. I'm gonna do a bit more research to see if there's a way I can prevent more false positives from occurring in future installs!