Help removing Malware from a Server

I'm not sure if my site was hacked or wtf happened but I got the "reported site attack" from my site. My anti-virus showed it as a html iframe. Does anyone have any experience with this?

I would really appreciate if someone could help me get this off my server/site as it's destroying my business.

open your pages weather its an html asp or php into file editor and u can see <iframe> codes in top of every file and in bottom of every file remove them from your all files once and save them that will remove this iframe virus from your pages but if u have asp, php, or cfm pages do make sure once check your db too may be it get hacked too and codes are generating from there ! if u want more help you can chat with me also !