New 'MACDefender' Variant Installs Without Admin Password Requirement

macdefender support note1
Antivirus firm Intego today reported that it has discovered a new variant of the "MACDefender" malware that ups the ante by not requiring an administrator password for installation. The step is accomplished by installing the application only for the current user.

Unlike the previous variants of this fake antivirus, no administrator's password is required to install this program. Since any user with an administrator's account - the default if there is just one user on a Mac - can install software in the Applications folder, a password is not needed. This package installs an application - the downloader - named avRunner, which then launches automatically. At the same time, the installation package deletes itself from the user's Mac, so no traces of the original installer are left behind.

The second part of the malware is a new version of the MacDefender application called MacGuard. This is downloaded by the avRunner application from an IP address that is hidden in an image file in the avRunner application's Resources folder.

Late yesterday, Apple issued its first public notice on the MACDefender malware, providing users with steps for avoiding or removing the software, as well as reporting that a Mac OS X software update to be released in the "coming days" will automatically find and remove MACDefender and its known variants. The update will also alert users if they are about to download one of the malware applications.

It is unknown whether protection against the new "MacGuard" variant will be included in the software update from Apple, but the company will almost certainly have to keep on its toes to address the quickly evolving threat.

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Top Rated Comments

stridemat Avatar
181 months ago
Perhaps Apple should issue an 'update' the makes Safari not open downloaded files automatically?
Score: 31 Votes (Like | Disagree)
Jolly Jimmy Avatar
181 months ago
One Word:

MACDEFENDER

;)
Not a virus. Honestly there should be a sticky thread or something explaining what a virus is.
Score: 14 Votes (Like | Disagree)
KnightWRX Avatar
181 months ago
Do you like contradicting yourself? We can go back and forth between "virus"/malware argument but what's the point.

I have not contradicted myself. Go back and forth on what ? Virus is a type of malware. Spyware is another. Trojans are yet another.

There are Mac malware out in the wild.
There aren't any Mac viruses out in the wild.

Both statements are true.
Score: 13 Votes (Like | Disagree)
longofest Avatar
181 months ago
the days of malware free macs are over! No surprise that Apple initially failed to acknowledge the problem.

The days of malware-free macs have BEEN over (https://www.macrumors.com/2006/02/16/mac-os-x-virus-trojan-summary/). This appears to be the first malware that is actually getting decent press coverage.
Score: 13 Votes (Like | Disagree)
*LTD* Avatar
181 months ago
apple should start catering to real mac users again, and not to the lowest common demonator = pc users!

Most Mac users used to be Windows users at one time or another. Including yours truly.

WTF is a "demonator"?
Score: 12 Votes (Like | Disagree)
griz Avatar
181 months ago
Uncheck "Open 'safe' files after downloading" in Safari Prefs.
Downloaded apps will not launch automatically if you uncheck this option in Safari. Not sure about other Browsers. So as long as you don't launch the installer, you are fine.
Score: 12 Votes (Like | Disagree)