404 error page not working for subservers

I’ve setup a htaccess file to be able to use my custom 404 error page (witch I use on my server with my main domain name), but for some wired reason (feels like if virtualmin have been hacked) nether my htaccess file or my custom 404 error page would work with any of my 3 subdomains (subservers). When ever there is a 404 error you see this damm image.

Another example is, links to images on my webserver are been replace with link to this damm image.

And when ever there is an 404 error, it shows an image that I don’t even have on my server. I’d right-click on that image and selected ‘View Image’ (to see where the image is located at), and I get this URL http://cdn.dsultra.com/images/image_redirect/shopwiki.com.png

This only happen with subservers, not with my main domain name.

Any idea? I did google that link and i see that otther ppl have been hacked and are getting the same image.