I'm using Google Chrome, and this has happened twice now.
The first website was selling a probiotic/fruit thing that wanted me to buy it for its health benefits or whatever. When I clicked the 'x' on the tab to close it, it opened a prompt that said "Wait! Are you sure you want to navigate away and miss this great deal?" or something to that effect. I clicked no and closed the tab.
The second website was an "FBI Warning" that listed my IP, home state, and county. When I clicked the 'x' to close the tab, it opened a prompt that said something like "FBI YOUR COMPUTER WILL BE DETAINED" over and over again until it went past the bottom of my screen. It was a.co.uk website.
This second website has me very concerned.
Around the time of this happening, I downloaded two new things. XKit for Tumblr and Hamachi for Minecraft.
I used add-ons on XKit that I thought would make Tumblr easier to use. Rainbow Bars, Timestamps, Music Downloader, etc. I can't remember what exactly I used, but that's about the gist of it. Also, I never actually download any music. I have since disabled and deleted the XKit extension in Chrome.
I used Hamachi to play Minecraft on a multiplayer server with a friend. I couldn't connect the first couple times, but my friend disabled their firewall and we were able to play on the server. We mucked around for about two hours while also chatting via Skype. I feel that may have been a mistake. I have since uninstalled LogMeIn Hamachi from my computer.
I ran Norton Security Quick Scan after the first website came up, but it came back with nothing. I'm running it again with a Full scan, so maybe it will come up with something. Nothing so far.
Why does this website keep coming up? Is my computer already infected? How do I make it stop?