I ended up on some site that tries to show there is a virus on my computer and asks me to install virus software - i know it's a trap. I can't close the window, navigate away, or even close the browser (firefox) without pop-up appear that ask me to click cancel or "save file". I am not going to click on anything like that. Any advice how to get out of this trap?
i think disabling java script, closing the tab, and then re-enabling it was much easier than any of the suggestions above.