Apple Responds Quickly to Evolving 'Mac Defender' Threat With Updated Malware Definitions

Yesterday, we noted that the attackers behind the "Mac Defender" malware had moved quickly to combat Apple's new security update, within hours releasing a new variant of the malware that was capable of skirting around Apple's new protection.

macdefender c xprotect

Xprotect.plist before (left) and after (right) latest update to address new Mac Defender variant

Fortunately for users, Apple has moved almost as quickly as the attackers, quashing any potential fears that the company might be slow to respond to each new threat that appears. As reported by Italian site Spider-Mac [Google translation], Apple has already issued an update to detect the new variant, pushing out a new entry for "OSX.MacDefender.C" to the Xprotect.plist file that contains the signatures for identifying malware.

After the update, users are indeed presented with a warning if they begin to download the latest variant:

macdefender mdinstall warning
As part of the security update earlier this week, Apple included a system to automatically update the Xprotect.plist anti-malware definitions every 24 hours, giving the company the ability to quickly push out new protection for Mac OS X Snow Leopard users. While this is unlikely to be the end of the Mac Defender attackers' efforts, it does appear that Apple is committed to responding and issuing updates to its users as quickly as the attackers can churn out new variants.

Top Rated Comments

0815 Avatar
154 months ago
The writers of this malware love to see Apple jumping through the hoops they make. This will on,y get worse with 10.7, as per Apples history, new OSes are filled with bugs and exploitable flaws.

You mean like windows where the general advice it not to install it until SP1 is released?
Score: 18 Votes (Like | Disagree)
NebulaClash Avatar
154 months ago
The attackers will always be one step ahead...

But if Apple stays only one step behind and closes the holes within 24 hours each time, the attackers will soon learn that there isn't that much to be gained by the effort. They'll have to try another approach.

You know, this relatively benign malware is, on balance, a good thing. This will educate Mac users not to click OK on software they did not choose to install. So that when something really serious shows up, they will know better thanks to this mild version that is merely annoying.
Score: 17 Votes (Like | Disagree)
beg_ne Avatar
154 months ago
The writers of this malware love to see Apple jumping through the hoops they make. This will on,y get worse with 10.7, as per Apples history, new OSes are filled with bugs and exploitable flaws.

Completely irrelevant. MacDefender doesn't take advantage of any flaw or bug in OS X. The only flaw in play here is people's gullibility.
Score: 12 Votes (Like | Disagree)
0815 Avatar
154 months ago
I wouldn't be surprised if the entire thing weren't stage-managed by Apple to give them an argument in favour of a move to an iOS-style Mac App Store-only software model. (Jailbreak your Mac, anyone?)

Here we go again - people running out of real arguments against apple clinging to stupid claims like this ....
Score: 11 Votes (Like | Disagree)
cnixon Avatar
154 months ago
You have to install this yourself.... it is NOT a virus... but maleware.

Not sure exactly how OSX is less secure? Maleware has been around for years for OSX.... just don't install the damn thing!

Maleware? What's maleware? Sounds like a line of men's lingerie. :confused:
Score: 11 Votes (Like | Disagree)
angrynstupid Avatar
154 months ago
Huh?



This doesn't bode well for Lion's release. Even if these threats don't indicate a material problem with OS X, the fact that Apple has been baited into an arms war makes OS X look less secure.

What kind of logic is this?
Score: 11 Votes (Like | Disagree)

Popular Stories

iPhone 15 Pro Buttons CAD Leak

iPhone 15 Pro Leak Reveals Unified Volume Button and Mute Button

Monday March 20, 2023 8:33 am PDT by
As previously rumored, the next-generation iPhone 15 Pro and iPhone 15 Pro Max will feature a unified volume button and a mute button, according to leaked CAD images shared in a video on the Chinese version of TikTok and posted to Twitter by ShrimpApplePro. Instead of separate buttons for volume up and volume down, the iPhone 15 Pro models are expected to have a single elongated button for...
iOS 16

iOS 16.4 for iPhone Nearing Launch With These 5 New Features

Monday March 20, 2023 11:50 am PDT by
Apple says iOS 16.4 is coming in the spring, which began this week. In his Sunday newsletter, Bloomberg's Mark Gurman said the update should be released "in the next three weeks or so," meaning a public release is likely in late March or early April. iOS 16.4 remains in beta testing and introduces a handful of new features and changes for the iPhone. Below, we have recapped five new features ...
voice isolation

iOS 16.4 Adds Voice Isolation for Cellular Phone Calls

Tuesday March 21, 2023 11:01 am PDT by
The iOS 16.4 update that is set to be released to the public in the near future includes voice isolation for cellular calls, according to notes that Apple shared today. Apple says that Voice Isolation will prioritize your voice and block out the ambient noise around you, making for clearer phone calls where you can better hear the person you're chatting with and vice versa. Voice...
original iphone auction

Factory-Sealed Original iPhone Sells for $55,000 at Auction

Friday March 17, 2023 1:08 pm PDT by
A first-generation iPhone still sealed inside its box sold for $54,904 at auction, which is more than $54,000 over the original $599 price tag of the device when it was released in 2007. The original iPhone was put up for sale by RR Auction on behalf of a former Apple employee who purchased it back when it first came out. Back in February, an original, sealed iPhone sold for over $63,000,...
airpodsd 3 purple 4

iOS 16.4 Seemingly References New AirPods and AirPods Case

Tuesday March 21, 2023 11:43 am PDT by
The iOS 16.4 release candidate version that was provided to developers today appears to hint at a new set of AirPods that could be coming in the near future. According to @aaronp613, the beta features references to AirPods that have a model number of A3048 and an AirPods case with a model number of A2968. There have been no rumors that new AirPods are on the horizon, and it is early for...
iOS 16

Apple Seeds Release Candidate Versions of iOS 16.4 and iPadOS 16.4 to Developers [Update: Public RC Available]

Tuesday March 21, 2023 10:25 am PDT by
Apple today seeded the release candidate versions of upcoming iOS 16.4 and iPadOS 16.4 updates to developers for testing purposes, with the software coming a week after the launch of the fourth betas. The RCs mark the final version of the software that will be provided to the public in the near future. Registered developers are able to download the iOS 16.4 and iPadOS 16.4 updates...
google bard

Google Opens Up Access to Bard AI Chatbot

Tuesday March 21, 2023 4:23 pm PDT by
Google today began allowing users to sign up to use Bard, its AI-powered chatbot that rivals Microsoft's Bing chatbot. First announced back in February, Bard is an experimental conversational AI service for Google Search. Those interested in Bard can join Google's waitlist to get access, and some users have reported getting invitation emails just hours after signing up. There are a long list ...
smart monitor m8 samsung

Deals: Samsung's iMac-Like Smart Monitor M8 Drops to Lowest Price of Year So Far With $250 Discount

Monday March 20, 2023 8:27 am PDT by
Samsung today kicked off a special "Discover Samsung" event, which will be a week-long savings event focusing on Samsung monitors, smartphones, TVs, appliances, and more. While some deals will stick around the entire week (through March 26), others will refresh every day. Note: MacRumors is an affiliate partner with Samsung. When you click a link and make a purchase, we may receive a small...