Windows 10 build 18238 (rs prerelease)

Windows 10 build 18238 (rs_prerelease) is an unleaked build of Windows 10 May 2019 Update. It was showcased in the session "Updating your existing Configuration Manager apps to MSIX" at the Microsoft Ignite 2018 conference.

It was also mentioned in a malware dataset provided to Kaggle community by Microsoft for Microsoft Malware Prediction Competition.