Unable to ping any website through terminal and network utility

Have you changed your network settings at any point? If so you may need to set the network to automatic and renew DHCP. Please see the instructions here: http://www.technobezz.com/mac-wont-connect-to-wifi/

Look at your hosts file. You can find it by clicking on the "Go' menu in the Finder and select "Go to folder..." then type "/etc/hosts". Copy the file on to your Desktop and open it with Text Edit.

You'll see the following lines at the top of the file :

##
# Host Database
#
# localhost is used to configure the loopback interface
# when the system is booting.  Do not change this entry.
##
127.0.0.1   localhost
255.255.255.255 broadcasthost
::1             localhost 
fe80::1%lo0 localhost

If you have others lines underneath, look for the domain "svenskadomaner.se" in a line such as 127.0.0.1 svenskadomaner.se. If you find a line like this, then your Mac redirects the domain to your localhost (your Mac) and of course it won't find the server. This is the technique to block a website on a computer. So delete the line, save the hosts file and replace the "/etc/hosts" file with the one that is on your desktop.

Then you can try again to go the website ;-)

Edit : It's possible that you don't have "127.0.0.1 svenskadomaner.se" in the file but something like "127.0.0.1 IP Address" where IP Address is the address of the servers of www.svenskadomaner.se.