1) Apple’s advice is to first try and navigate away from the dangerous fake antivirus page by “force-quitting” this dangerous application. Apple support describes the process as “chose Force Quit from the Apple menu (or press Command—Option-Esc), then choose the unresponsive application in the Force Quit window, and click force Quit.”

2) In some scenarios, the Apple browser may automatically download and launch the installer for this malicious software. If this happens, Apple says “cancel the installation process; do not enter your administrator password.” Deleting the installer immediately involves going into the Downloads folder (or your selected download location) and dragging the installer to the Trash and emptying the Trash.

3) If you do happen to unexpectedly see an installation screen from Mac Defender, do not install the application. The Mac Defender installation screen looks like the normal Mac OS X installer screen, which is why some have been fooled by it. Uncheck the “Open ‘Safe’ files after downloading” option in Safari, or similar options in other browsers. If a browser asks you if you want to run an installer when you did not expect to download an installer, always click the No or Cancel button.

4) Of course, you can always use MacNet for ongoing protection against Mac-based malware, even though the Apple Macintosh has been far less a target for malware than Windows.