Hi Viggos, welcome to the forums!
"Spoof" means that someone is sending you hundreds of packets, making your connection lag out.
The only thing that I'm aware of that will allow you to stop this - is to find out the IP Address, call your ISP and get them to block the address.
Your ISP will be able to tell you what IP Address is spoofing you.
Or, if it's multiple...ask them to put you on a "Dynamic IP" which means everytime you restart your router, you get a new IP.
As a preventative method, can you please follow the Prework steps located here, and one of the security team will be along shortly to have a look at it and make sure computer is nice and clean.
http://www.pchelpforum.com/hijackthi...a-prework.html