The Mac operating system is relatively impervious to viruses and other malware. However, Apple reports in June 2011 of a phishing scam that purports to provide software to remove a virus from an infected machine. Instead of downloading anti-virus software, however, you download a virus that seeks out your credit card information. The phishing scam uses the names MacDefender, MacProtector and MacSecurity, according to Apple. If you've installed the virus, it's relatively easy to remove.
Remove the installer if your browser begins downloading it automatically.
Quit the browser, using either "File," and then "Quit;" the shortcut "Option-Q" or forcing the browser to quit -- "Command-Option-Esc" -- if necessary.
Open the downloads folder and drag the installer file to the trash can.
Select "Empty Trash" from the File menu in the Finder.
Either close or move the window that is beginning a scan of your computer.
Open the Applications Folder. From the Utilities folder, launch "Activity Monitor."
Select "All Processes" from the pop-up menu that appears.
Review the list of processes in the Process Name column. Select the virus -- MacDefender, MacSecurity or MacProtector -- and click the "Quit process" button. Then select "Quit."
Quit the Activity Monitor application using "File," and then "Quit" or "Option-Q."
Find the virus -- MacDefender, MacSecurity or MacProtector -- in the Applications folder.
Drag the virus to the trash, and then select "Empty Trash" from the File menu in the Finder.