I was looking at recipes on Pinterest and a window popped up saying Norton anti-virus software detected 5 viruses trying to get into my computer. I should click on the download button to download new software to combat it. My Norton anti-virus has never done this before so I was suspicious. When I tried to "X" out of the window it added another window telling me to click on the download button. Again I tried to "X" out of that window and it added another window telling me my computer would be seriously damaged if I "X"-ed out. So I tried to "X" out of the whole screen and I couldn’t do that either it wouldn’t respond. I had to hold the on off button on my tower to completely shut down the whole computer along with my peripherals (printer, speakers, scanner, etc) in order to escape. I kept it off for about 15 minutes and when I turned it back on it was as if it never happened. When I checked my Norton software site it said everything was up to date and no problems detected. I think it was someone trying to infect my computer.