Recently, I have found some websites in my history which I never visited, might this caused by a kind of virus, actually the sites are so embarrassing and bad. No one used my computer. the websites are: bearwww.com & silverdaddies.com I think, and there were around twinty pages visited in the history at certined times. could this be a virus or my network was hacked by some body, I use Avast anti virus and do not but a firewall. please tell me if this could happen without visiting such these bad websites.
Hint : the fisrt website ( bearwww.com) was able to be opened at the moment I found it in the history, but when I delete the history and tried to open the site again, I was not able to as they say I should have a profile to enter the site parts.