iProxy

I deleted the file and everything went back to normal.
Thanks again to everyone and good luck. Totally outdated subject.

You'll want to delete the "blog" folder in your "info" folder as that shouldn't be there and the dynamic URL isn't working from the software.

When you save that form, the software makes an HTTP request to the URL that is entered to ensure it is valid. Your server is blocking that request, which is why it says it is invalid.
I would recommend contacting your host to ensure that your server can make HTTP requests to itself. Unfortunately, this is not a software issue.

Please make any feature suggestions in Feedback forum.
 

/_logs is not a folder in our software so you would need to consult your hosting provider for assistance.

Index.pl, index.cgi and index.html are files that do not exist in a default installation of IPB inside of the /admin folder.
My guess is when you try to access domain.com/admin/, your host is first trying to find file index.html which does not exist. It then tries to find index.pl which also does not exist. It then tries index.cgi which also does not exist. It succeeds when trying index.php.
The order in which files are tried are managed in the DirectoryIndex directive of the server.
Each of those “not founds” would trigger a 404 error. This is not an IPB problem. You can ignore the warning or have your host make the default file index.php and to try it before trying other variations. 

The other issue is that an attacker is just trying to guess files and randomly just trying to load /admin/index.cgi or /admin/index.pl, etc.  If this is the case, there is nothing you can do to block it within IPB as it's trying to attack something outside of the software.  
In either case, it's a server/hosting related issue.  

We made a patch available earlier today that fixes this issue. If you are using an affected version of 4.7.9, it can be obtained from the AdminCP > System > Support page (top left box will tell you if there is a patch or update available)

In this case it is better to ban the IPs by the HTACCESS (a few days). Then do a search for their host with WHOIS. If it is not Asian or Russian you can contact them by abuse@... by sending a copy of the spam.