Overview
These pop-ups are carefully crafted to look and sound authentic, but they are fraudulent. These pop-ups take advantage of social engineering techniques, your busy schedule and incredulousness concerning this type of security threat.
What to do and What NOT to do...
What to do:
Shutdown you computer immediately. Reboot it and run a full virus scan!
What NOT to do:
Do NOT click the X on the pop-up window to close it. And, of course, don't click anything inside the box either. If you click the X to close the box, it will close the pop-up, HOWEVER it will also transparently download a virus onto your computer - all without your knowledge!
Notes:
There are many variations of this bait (like pop-up's that claim to clean your registry), so you need to apply the same technigue above to any of these fake pop-up boxes. The con-artists and criminals are always tweaking these messages in order to fake you out - so much so, these pop-ups have a security term of there own: Scareware.
If you are in an Administrator account and click any part of the pop-up, even the X (as discussed above) you will wreak havoc on your computer! Although you can still get infected from a limited account, a privileged account (such as an Administrator account) will give the keys of your entire operating system over to this virus!
Microsoft has written about this problem [please read this]: http://www.microsoft.com/security/antivirus/rogue.aspx
Some Examples of
Fake Anti-virus Pop-ups
Microsoft has written about this problem [please read this]: http://www.microsoft.com/security/antivirus/rogue.aspx
Conclusion
If you should receive one of these fake pop-ups
(you can usually tell because they pop up instantaneously while
surfing the internet), then you should shutdown you computer immediately and then reboot it and run a full scan of your anti-virus software!