Did the site replace Cnet's in the tab/window, open in a pop-up, display as an advertisement within the Cnet pages, or open in a new window? (The link you provided just links to their website.) Could you have clicked on an advertisement? With the recent round of malicious ads I'm keeping my eyes open, just in case.
This one tip will help you sleep better tonight
A few seconds are all you need to get a better night's rest.