Securing your Mac from the new MacGuard malware variant

The MacDefender phishing malware for OS X has caused a bit of concern in the Mac community. People who inadvertently visit the false "Apple Security Center" Web site are downloading the installer for the scam software and installing it. This has previously required users to interact with the software installer and provide an admin password to install the package; however, a new variant installs the program under the current user’s account and uses an install option that does not require an admin password.
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