That is not real. Someone is sending spam most likely through Messenger, trying to get you to install a trojan or virus.

That could be from an infected site that you were on when the message popped up. If you clicked anywhere on the warning, including the close (X) button, it MAY have installed malware on your system.

Below is a link to bleepingcomputer.com instructions for removal. If it is too involved for you to feel comfortable, scroll to the bottom of the page and you will see a warning "This is a self-help guide. Use at your own risk." and within the paragraphs following that are links to the bleepingcomputer forum where you can get free expert help in removing any infection. NOTE: Read the rules for posting in their forum, following instructions to-the-letter, do exactly what they tell you to do when they respond to your posting, no more/no less. Also, be patient, they process the questions for help in the order received.

You need to update the following. The Plugin version(s) shown below was/were submitted with your question and is/are out of date. You should update to avoid known security issues with the version(s) you have installed. Click on "More system info..." to the right of your question to see what was included with your question.

• Shockwave Flash 10.2 r159
• Next Generation Java Plug-in 1.6.0_24 for Mozilla browsers

1. Check your plugin versions on either of the following links':
   • http://www.mozilla.com/en-US/plugincheck/
   • https://www-trunk.stage.mozilla.com/en-US/plugincheck/
   • Note: plugin check page does not have information on all plugin versions
   • There are plugin specific testing links available from this page:
     • http://kb.mozillazine.org/Testing_plugins
2. Update the Flash plugin to the latest version.
   • Download and SAVE to your Desktop so you can find the installer later
   • If you do not have the current version, click on the "Player Download Center" link on the "Download and information" or "Download Manual installers" below
   • After download is complete, exit Firefox
   • Click on the installer you just downloaded and install
     • Windows 7 and Vista: may need to right-click the installer and choose "Run as Administrator"
   • Start Firefox and check your version again or test the installation by going back to the download link below
   • Download and information: http://www.adobe.com/software/flash/about/
     • Use Firefox to go to the above site to update the Firefox plugin (will also install plugin for most other browsers; except IE)
     • Use IE to go to the above site to update the IE ActiveX
   • Download Manual installers.
     • http://kb2.adobe.com/cps/191/tn_19166.html#main_ManualInstaller
     • Note separate links for:
       • Plugin for Firefox and most other browsers
       • ActiveX for IE
3. Update the Java plugin to the latest version.
   • Download site: http://www.oracle.com/technetwork/java/javase/downloads/index.html (Java Platform: Download JRE)
     • Be sure to un-check the Yahoo Toolbar option during the install if you do not want it installed.
   • Also see "Manual Update" in this article to update from the Java Control Panel in Windows Control Panel: http://support.mozilla.com/en-US/kb/Using+the+Java+plugin+with+Firefox#Updates
   • Removing old versions (if needed): http://www.java.com/en/download/faq/remove_olderversions.xml
   • Remove multiple Java Console extensions (if needed): http://kb.mozillazine.org/Firefox_:_FAQs_:_Install_Java#Multiple_Java_Console_extensions
   • Java Test: http://www.java.com/en/download/help/testvm.xml

That is a fake animated scanner page which claims you are infected and then suggests you download a .exe which will be what really infects the computer if using Windows.

Firefox does not have any form of scanner and Mozilla would never provide such a download.

Both James and Helper7677 are correct. That was a fake anti-virus program, an example of scareware. What you describe ties in with the reports of this variant that appeared a while ago - see http://www.theregister.co.uk/2011/03/02/rogue_av_mimics_firefox

"Some of the sites that redirect to the scam include columbia.<removed>.com, www.<removed>.org, <removed>.com. When successful, the redirected page pushes the file InstallInternetDefender_xxx.exe, where “xxx” is a number that changes frequently."

You were being pressured to download "Security Central" instead of "Internet Defender" but it's the same scam. I hope you followed Helper7677's advice for removing the traces of this rogue program; and if it's any consolation this sort of scareware slips past many (if not most) antivirus programs.

As long as the user has not downloaded the suggested .exe and run it, then the computer should not be infected.

These fake animated scanner pages with Windows XP theme are much more obvious in being fake when a Linux or Mac user encounters it.

James:

Some of the fake AV programs will download malware to your system if you click anywhere on the "warning" screen; anywhere, including the "X" close button for that tab or screen.

• Best approach is to immediately close your browser from Task Manager (Windows) and scan your system with several malware scanners for safety and assurance.
• Problem is, too many users
  • do not know what is on their system(i.e., whether the message is from an installed program)
  • do not take the time to look at the screen and realize that it is fake
  • do not keep themselves informed as to know what is happening on the internet today.

Helper767 in second paragraph:

"...scroll down to the bottom of the page..." what page? this Firefox Help page? the bottom of your entry? or the some page at bleepingcomputer.com?