How to remove a Virus or Malware in a Mac.


Move or close the Scan Window.
Go to the Utilities folder in the Applications folder and launch Activity Monitor.
Choose All Processes from the pop up menu in the upper right corner of the window.
Under the Process Name column, look for the name of the app and click to select it; common app names include: MacDefender, MacSecurity or MacProtector.
Click the Quit Process button in the upper left corner of the window and select Quit.
Quit Activity Monitor application.
Open the Applications folder.
Locate the app ex. MacDefender, MacSecurity, MacProtector or other name.
Drag to Trash, and empty Trash.

Malware also installs a login item in your account in System Preferences. Removal of the login item is not necessary, but you can remove it by following the steps below.

Open System Preferences, select Accounts, then Login Items
Select the name of the app you removed in the steps above ex. MacDefender, MacSecurity, MacProtector
Click the minus button

Pretty Easy Stuff!