You can consult me. PM me if you want, I'll be able to u provide you website security solutions to help prevent from hackers gaining access and defacing content.
Reupload your index page. Hackers often attack a site by substituting this single file. Otherwise, if your site is database-powered you need to restore it from a previous backup to get your site running again.
Can't figure out who or what gencnesil is, but a web search on it seems mostly to return results mentioning remote SQL injection and remote file include vulnerabilities.