Wrong init

Hello. I have a server running 7.2 and today it started to jam on the net, i maked a reboot, but it will not come up, it sayes kernel panic atemted to kill init. I found in /sbin a init program on 15K with tha same rights as a renamed initrZ9 on 470K Is that a hackning of my server? I tryed to move it back but the new init was write proteced even for root. somebody know? Tage from Denmark