The false perception that Mac OS X is relatively safer than Windows operating system has finally been shaken. Lately there are bus load of fake anti-virus malware that engages in phishing attempt on Mac OS X users. The working of fake anti-virus malware is similar to Windows version – the malware informs user that the Macintosh is infected with a virus, and then offers user a fake anti-virus software in the name of MacDefender, MacProtector and MacSecurity, etc.

The anti-virus program offered is actually fake and the offer is malicious in intent. The main aim of the malware is to steal user’s credit card information for fraudulent purposes. This type of phishing attempts have been very common on Windows platform, but has just recently been “ported” to Mac OS X platform, which, unfortunately, is vulnerable too.

After days in denial and blames users for not exercising caution when visiting unknown websites and downloading unsafe programs, Apple finally acknowledges the malware issue, and intends to release a Mac OS X software update that will automatically find and remove Mac Defender malware and its known variants. The update will also help protect users by providing an explicit warning if they download this malware.

While waiting for the update, Apple provides that a guideline on how to avoid or manually remove this malware.

How to avoid installing this malware

If any notifications about viruses or security software appear, quit Safari or any other browser that you are using. If a normal attempt at quitting the browser doesn’t work, then Force Quit the browser.

To Force Quit an application, choose 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.

Alternatively, press and hold Option then right click the application’s icon in the Dock and choose Force Quit from the contextual menu.

Or, in Mac OS X v10.5 or later, press Command + Option + Shift + Esc for three seconds to force quit the front-most application.

In some cases, your browser may automatically download and launch the installer for this malicious software. If this happens, cancel the installation process; do not enter your administrator password. Delete the installer immediately using the steps below.

  1. Go into the Downloads folder or your preferred download location.
  2. Drag the installer to the Trash.
  3. Empty the Trash.

How to remove this malware

DO NOT ever provide your credit card information under any circumstances.

  1. Move or close the malware’s Scan Window.
  2. Go to the Utilities folder in the Applications folder and launch Activity Monitor.
  3. Choose All Processes from the pop up menu in the upper right corner of the window.
  4. 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.
  5. Click the Quit Process button in the upper left corner of the window and select Quit.
  6. Quit Activity Monitor application.
  7. Open the Applications folder.
  8. Locate the malware app, i.e. MacDefender, MacSecurity, MacProtector or other name.
  9. 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.

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