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.

Popular Stories

iPhone 17 Pro Lower Logo Feature 1

iPhone 17 Pro Coming Soon With These 14 New Features

Monday June 30, 2025 1:08 pm PDT by
Apple's next-generation iPhone 17 Pro and iPhone 17 Pro Max are less than three months away, and there are plenty of rumors about the devices. Apple is expected to launch the iPhone 17, iPhone 17 Air, iPhone 17 Pro, and iPhone 17 Pro Max in September this year. Below, we recap key changes rumored for the iPhone 17 Pro models:Aluminum frame: iPhone 17 Pro models are rumored to have an...
Apple Watch Ultra Night Mode Screen

Apple Watch Ultra 3 Launching Later This Year With Two Key Upgrades

Wednesday July 2, 2025 1:13 pm PDT by
The long wait for an Apple Watch Ultra 3 appears to be nearly over, and it is rumored to feature both satellite connectivity and 5G support. Apple Watch Ultra's existing Night Mode In his latest Power On newsletter, Bloomberg's Mark Gurman said that the Apple Watch Ultra 3 is on track to launch this year with "significant" new features, including satellite connectivity, which would let you...
A18 Pro Chip

New MacBook With A18 Pro Chip Spotted in Apple Code

Monday June 30, 2025 8:05 am PDT by
Apple is developing a MacBook with the A18 Pro chip, according to findings in backend code uncovered by MacRumors. Earlier today, Apple analyst Ming-Chi Kuo reported that Apple is planning to launch a low-cost MacBook powered by an iPhone chip. The machine is expected to feature a 13-inch display, the A18 Pro chip, and color options that include silver, blue, pink, and yellow. MacRumors...
iPhone 17 Pro Lower Logo Magsafe

iPhone 17 Pro's New MagSafe Design Revealed in Leaked Photo

Wednesday July 2, 2025 8:37 am PDT by
The upcoming iPhone 17 Pro and iPhone 17 Pro Max are rumored to have a slightly different MagSafe magnet layout compared to existing iPhone models, and a leaked photo has offered a closer look at the supposed new design. The leaker Majin Bu today shared a photo of alleged MagSafe magnet arrays for third-party iPhone 17 Pro cases. On existing iPhone models with MagSafe, the magnets form a...
macbook air spacegray purple

Apple Planning to Launch Low-Cost MacBook Powered By iPhone Chip

Monday June 30, 2025 3:20 am PDT by
Apple is planning to launch a low-cost MacBook powered by an iPhone chip, according to Apple analyst Ming-Chi Kuo. In an article published on X, Kuo explained that the device will feature a 13-inch display and the A18 Pro chip, making it the first Mac powered by an iPhone chip. The A18 Pro chip debuted in the iPhone 16 Pro last year. To date, all Apple silicon Macs have contained M-series...
iOS 18

Apple Releases Second iOS 18.6 Public Beta

Tuesday July 1, 2025 10:19 am PDT by
Apple today seeded the second betas of upcoming iOS 18.6 and iPadOS 18.6 updates to public beta testers, with the betas coming just a day after Apple provided the betas to developers. Apple has also released a second beta of macOS Sequoia 15.6. Testers who have signed up for beta updates through Apple's beta site can download iOS 18.6 and iPadOS 18.6 from the Settings app on a compatible...
Wi Fi WiFi General Feature

iOS 26 Adds a Useful New Wi-Fi Feature to Your iPhone

Wednesday July 2, 2025 6:36 am PDT by
iOS 26 and iPadOS 26 add a smaller yet useful Wi-Fi feature to iPhones and iPads. As spotted by Creative Strategies analyst Max Weinbach, sign-in details for captive Wi-Fi networks are now synced across iPhones and iPads running iOS 26 and iPadOS 26. For example, while Weinbach was staying at a Hilton hotel, his iPhone prompted him to fill in Wi-Fi details from his iPad that was already...
maxresdefault

Five Features Coming to AirPods Pro 3

Friday June 27, 2025 10:52 am PDT by
Apple hasn't updated the AirPods Pro since 2022, and the earbuds are due for a refresh. We're counting on a new model this year, and we've seen several hints of new AirPods tucked away in Apple's code. Rumors suggest that Apple has some exciting new features planned that will make it worthwhile to upgrade to the latest model. Subscribe to the MacRumors YouTube channel for more videos. Heal...
replay all time playlist apple music

Apple Music Debuts All-New Personalized Playlist

Monday June 30, 2025 7:16 am PDT by
As part of its 10-year celebrations of Apple Music, Apple today released an all-new personalized playlist that collates your entire listening history. The playlist, called "Replay All Time," expands on Apple Music's existing Replay features. Previously, users could only see their top songs for each individual calendar year that they've been subscribed to Apple Music, but now, Replay All...

Top Rated Comments

stridemat Avatar
184 months ago
Perhaps Apple should issue an 'update' the makes Safari not open downloaded files automatically?
Score: 31 Votes (Like | Disagree)
Jolly Jimmy Avatar
184 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
184 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
184 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
184 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
184 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)