On Wednesday, Windows users started sharing details on a strange update delivered by Microsoft. The update itself used a string of random characters in the description, along with resource URLs using a similar format pointed at.gov,.mil, and.edu addresses. Microsoft confirmed Wednesday afternoon that the update was a test and was removed from the list of available updates. It isn’t clear what files were modified by the update, and if it was downloaded and installed prior to removal, it’s not clear what was modified.”]
Source: https://www.csoonline.com/article/2988095/strange-windows-update-creates-confusion-panic.html