New Variant of 'Mac Defender' Quickly Evades Apple's Security Update as Cat-and-Mouse Game Begins

macdefender dialog box
As we noted yesterday, Apple released Security Update 2011-003 for Mac OS X Snow Leopard, a system update addressing the "Mac Defender" malware threat that has been running in the wild under several different variants for the past month. The update provides tools for automatically removing the malware, as well as protection against future infections. But as reported by ZDNet, a new variant of the malware capable of circumventing Apple's update has already appeared. popping up within hours of Apple's software release.

Hours after Apple released this update and the initial set of definitions, a new variation of Mac Defender is in the wild. This one has a new name, Mdinstall.pkg, and it has been specifically formulated to skate past Apple's malware-blocking code.

The file has a date and time stamp from last night at 9:24PM Pacific time. That's less than 8 hours after Apple’s security update was released.

Apple has prepared for this eventuality by including automatic daily updates of malware definitions with the software update, enabling it to quickly deploy protection as new variants and entirely different pieces of malware surface. Consequently, Apple should be able to respond to the new threat relatively quickly, although the speed with which the new variant appeared suggests that those responsible for the malware will not be going away easily.

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Top Rated Comments

laurim Avatar
169 months ago
I'm amazed people are still stupid enough to manually download and run this considering all the press coverage it has received.
I'm amazed people have nothing better to do than create viruses and malware all day. Imagine what could be achieved if people used their time and skills to do something useful for society. Hope they goof up, get traced and held accountable.
Score: 35 Votes (Like | Disagree)
chrono1081 Avatar
169 months ago
Props to those guys beating Apple at this.

As much as you can hate windows, MS has been very serious about security on Windows with a much tighter security system in Windows 7. Not saying that they had already not needed that, but they have been very careful and have come strong on viruses and malware.

Apple, you need to tighten up here.

Nice troll attempt. If MS was serious about security they would start by removing the registry.
Score: 19 Votes (Like | Disagree)
Popeye206 Avatar
169 months ago
LOL! Funny.... looks like the crooks are hard at work to stir the pot on the Mac side.

Doesn't scare me. I don't install what I don't know. Malware is just annoying.
Score: 19 Votes (Like | Disagree)
Popeye206 Avatar
169 months ago
Props to those guys beating Apple at this.

As much as you can hate windows, MS has been very serious about security on Windows with a much tighter security system in Windows 7. Not saying that they had already not needed that, but they have been very careful and have come strong on viruses and malware.

Apple, you need to tighten up here.

The thing is, Malware is user initiated. Unless MS, Apple or whoever knows about a specific threat, you can't stop someone from offering a user the opportunity to download something. If they say yes, they invite the crooks in. Viruses is another story. These have to go around security in the OS to install themselves and extract information or change system settings to cause harm. Obviously the second is way more dangerous because you don't see it coming.

I only point this out because what the heck is Apple suppose to do any different? If you don't know what to not allow, or look for, you can't stop someone from wanting to install software.
Score: 16 Votes (Like | Disagree)
Popeye206 Avatar
169 months ago
Makes you wonder if nokia/ms are behind this! :)

LOL!

I've always wondered is the Virus protection companies aren't the ones that hire suspect engineers from places like Russia to keep the need for them rolling. Wouldn't be too surprising if it was true.
Score: 14 Votes (Like | Disagree)
BaldiMac Avatar
169 months ago
Props to those guys beating Apple at this.

As much as you can hate windows, MS has been very serious about security on Windows with a much tighter security system in Windows 7. Not saying that they had already not needed that, but they have been very careful and have come strong on viruses and malware.

Apple, you need to tighten up here.

What is Microsoft doing that Apple is not that would currently prevent a Mac Defender type attack? Daily definition updates of an anti-malware scanner is the most appropriate strategy. Outside of preventing the user from installing unapproved applications, I'm not sure what else you can do.
Score: 14 Votes (Like | Disagree)