Hi guys, I've been using my Macbook Air late 2010 for some time and it's still running on snow leopard. Now I've got the pop up blocker clicked in the safari preferences. However I have recently downloaded some torrents, now on a few occasions I have clicked on to websites and have noticed that pop-up ads have appeared in a separate window, usually gambling site ads etc. Do I have any kind of malware? I have run Clamxav but it has come back with nothing!!