Windows 8.1 build 9428

Windows 8.1 build 9428 is part of the Milestone Preview. It was compiled on 2013-06-12. There's a public screenshot of it but it was confirmed to be fake. 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"