I have had a similiar message just once - a couple of days ago. Hope nothing bad is going to happen. Love this place!!!

I've had it happen twice this weekend. I have McAfee.

I need to join this club also. Sat. I was PMing someone and a message came up that I had been attacked by virus and I must buy this brand of antivirus. This crazy screen blocked me from my real antivirus(cybernet)so I could not run a scan. After I unplugged everything and reconnected it seemed fine. I contacted the Admin, he suggested it might be adware. So off to the store, bought a new repair antivirus finally got it installed, 'puter' been working fine since. Hope to never have this happen again.

I'm talking to a few other webmasters whose users are reporting the same thing. It looks like it started on 4/23. Please let me know if you continue seeing this warning any time since Monday morning.

Oh my goodness I purposedly came here to ask for help as this very thing happened to me over the weekend, now i can't get rid of these stupid ad pop ups...so annoying...I will keep on eye on this thread.
thanks.
p.s.
I don't use norton, I use avast and when i ran a scan it showed nothing.
thanks for the knowledgable quilters.

That sounds like malware which hit my daughters 2 laptops. You'll need something like PC Tools--McAfee didn't pick it up and neither did Norton when my cousin had it on her computer. It took her 8 continuous hours to clean it up! She sent me this link, http://forums.majorgeeks.com/showthread.php?t=35407 to get rid of that. Good luck to you!

screenshot

hit your prnt screen button
open Word if you have it, I use Irfanview for images
open a new file
click in the open area
hit Control V to copy your image
save

I use Vista so it may be different for each individual

Thanks so much for the above link....for now all seems to be well...well for me as long as i can nagvigate around..lol I did save the above link. Thanks again. Amazing group we have here.