This is not fake but it is NOT CFW either. I extracted (easy) the firmware ALL of the files are from firmware 4.0 except license.xml which has been modified with this extra message
"AnonymousJailbreakers jailbreak agreement. december 2011. 4.00 JAILBREAK CREATED BY: AnonymousJailbreaker (AnonyJbreak) THIS IS THE NEW UPDATED JAILBREAK BUT IT HAS LESS FEATURES SO IT WILL NOT BE CORRUPT! I COULDNT USE THE INSTALL PACKAGE FILES DUE TO ERRORS SO SORRY ABOUT THAT! & ENJOY MY JAILBREAK! ALL OF THE SAME TERMS AND CONDITIONS FROM THE PREVIOUS JB STILL APPLY!!!"
When/if CFW 4.0 is released it will be front paged here so don't bother yourself with idiotic bs.