I’ve been noticed that my Firefox browser currently pop-up some weird web pages while idling. Tried with anti-virus software scanned the whole folders ends up nothing. Then I found even when I browse Google it has shown ‘Blocked loading mixed active content “http://vk.com/”’ like so:
Then I suspect there might be some Add-ons triggered the pop-up. Lucky that I had a few extensions so I located the virus extension within minutes.
Remember to avoid this one: YouTube Adblock 2.1.3