i don’t think it’s about a hack. Try checking the permission of writing on the index file (go to Total Commander or whatever ftp access program you’re using and go to “change attributes” on the index file and make it under the protocol 777- just for a short while to see if it’s working like that)
I think the all in 1 seo pack is trying to access your index.php. But this doesn’t mean it’s hacking your site.
So, make sure the plugin has all the rights it needs in order to work properly.
That’s all it goes through my mind right now. Hope it will help.
