It only happened once, but definitely through empireminecraft.com. I was redirected to an advertisement which attempted to make me download "setup.exe" in order to "update my video player" to "view the webpage." I think it had an Adobe Flash logo somewhere on it.
This should only really really happen if youve download malware or adware that is now infesting your computer. It's happened to me before. I suggest getting Malware Antibytes and scanning your computer, as that is what helped me get rid of my adware.
Nah, I've seen it on ad sites before (usually the ads.doubleclick.something), but I run all kinds of anti-malware programs, and I've only been on emc.gs. It didn't "pop up" that was the wrong word. It redirected. I'll see if I can duplicate it before I worry.
