Thanks for the reports. I have submitted both the Launcher and LauncherHelper to Microsoft for review so they can update their definitions to avoid falsely identifying viruses in the current versions of those applications.
Previous versions of both applications (from 9.50.021) were submitted to Microsoft, but they treat the new versions that came along in 9.50.024 independently of the previous versions. Though they've been publicly released for about a couple weeks now, it appears a recent definitions change on the Windows Defender side caused it to start flagging them in the last day or so.
Funnily enough, as I was in the process of submitting the LauncherHelper for review based on technoid's report (and thank you for the screenshot, which gave me the info I needed to complete the submission!), the same alert that tharbin reported above popped up the Launcher in my own installation. So I submitted that immediately after.
Looking ahead we want to find a way to prevent this from happening. In the meantime, you can refer to my directions in post #1 for how to restore the applications that Windows has quarantined.