Windows 8.1 build 9428

Windows 8.1 build 9428 is a build of Windows 8.1. There's a public screenshot of it but it was confirmed to be fake due to identifying itself as "Windows 8.1 Milestone Preview", while earlier and later builds identify themselves as "Windows 8.1 Preview". It was made by a BetaArchive member, despite its spread all over the internet tech news outlets.

However, the build string itself was confirmed to belong to a genuine build; since an internal WinJS build originating from the Windows Store also had that build string.

The package name was: "Microsoft.WinJS.2.0.Preview_1.0.9428.0_neutral__8wekyb3d8bbwe"