system
6
Just to add this, don’t download any keygens, because this is how most of the people got infected with this virus.
So far the sites we know that it would be good to block them are these:
proxim.ircgalaxy.pl
1.mezzicodec.net
smart-security.biz
ntnrkrnlpa.info
You can enable URL blocking in avast and add this sites to be blocked.