URL redirecting to a random site

i am using a clean install of win 7
I was testing bing, i typed in a forum i used to visit…i clicked the hyperlink and instead of ending up at the forum a random page popped up asking for a plugin to be installed…i exited the page…i typed the url of the main site into my web address bar and again was redirected to another random site.
I exited firefox and used google and clicked the hyper link to the forum from there and then the website appeared correctly? what could this be? cross site scripting? search engine poisoning? maybe the webmaster of the site was responsible.
i have ocd…
Answer #1
Your browser may be hijacked.
Answer #2
my browser is not hijacked.
Answer #3
Screenshots would help.
Also the URL of the website you were trying to visit, as we could also test it on our end.
Answer #4
What were search queries/site URL ?