Win Defender Detecting Virus when I open OBS

I doubt this is a false positive. You’re probably in danger. This directory is the cache of the obs internal browser, so it seems you navigated to some malware distributing website with the obs internal browser, so that trojan was downloaded and is now as cached object in the browser cache. If it is also present as live file on your harddrive isn’t clear. I don’t know if the internal browser has some download functionality. If it has, there is danger. If it doesn’t, it might be sufficient to remove that file. In either case, you should scan your computer thoroughly and completely with Windows defender and delete found malware files.