University of Vermont

Information Technology

Fake Antivirus Targets Macs

Do not install false Mac antivirus software.
Do not install false Mac antivirus software. (image:

A new malware threat has been identified for Mac users that presents itself as an antivirus application called "MACDefender" (pretending to be a legitimate Mac antivirus program of the same name), "Mac Security" or something similar.  The malware attempts to install itself through hijacked websites and exploits the some web browsers' preference to open "safe" (actually meaning "of a known file type," such as a PDF, or in this case, an installer) files automatically after downloading.

These false antivirus programs cannot install itself without someone clicking "Continue" on its install prompt and providing the Mac's administrator password.  If you are suddenly prompted with an installation screen for antivirus software on your Mac, click Cancel to abort the installer.

If you think you may have already installed false antivirus software, you can try following these instructions for detection and removal, or contact the Helpline or your college or department's IT support.

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