Finally a milestone version of the most awaited Windows 8  has been leaked. The build is legitimate and not fake as confirmed by most reputable sources. The ISO is currently available on private FTP site, but soon expected on famous torrent sites like the Pirate bay and ishohunt.

Build leak: Windows 8 Build 7850 Milestone 1 Build
Build String: 6.1.7850.0.winmain_win8m1.100922-1508_x86fre_client-enterprise_en-us.iso
Size: 2.45 GB (2,637,101,056 bytes)
MDA Hash: 6E491914 6456F3C7 E1EEE202 536F8A4F 9CBE7893

CRC: N/A
SHA-1: N/A

This is the Final M1 version (6.1), will be entering BETA soon. The OEM will be available in late 2012 and possible retail availability in January 2013.