Mac OS X Struck By Severe Security Hole 559
An anonymous reader writes "Macworld is reporting about a new security hole in Mac OS X that can be exploited to compromise a system if the user simply visits a web site with Safari. Currently, no vendor patch is available. Secunia has a demonstration of the vulnerability and suggestions for temporary workarounds."
I guess the H4x0rs (Score:5, Funny)
Seriously (Score:3, Insightful)
Auf Wiedersehen!
Re:Seriously (Score:3, Insightful)
For the most part, it always requires less skill to break something than to get something working. i.e. my ten year old nephew can destroy my car if I let him under the hood - it doesn't make him as talented as an automotive engineer. With some knowledge, he can do more sophisticated sabotage, but he still isn't as skilled as the average engineering undergrad.
The analogy works in other places: in sports, defensive teams succeed way more often than high flying offensive team
Re:Seriously (Score:3, Insightful)
I can see where you're coming from, but I think that's a poor analogy.
You nephew is more like a beta tester that can find bugs easily, as he can do something wrong or unexpected and "break" an application. Finding ways around security is something else; sometimes it's just exploiting a bug but sometimes there's a lot more to it (research, investigating, and some coding).
The I be
Re:Seriously (Score:5, Insightful)
I think your analogy doesn't really support your point and in fact supports the GP. Reformed bank robbers are not really security experts who can design new security systems, I think you your opinion is based more on movies than on reality. Similarly, hackers are romanticized, their skills exaggerated, in movies and in ill informed nerd mythology spread by sites like slashdot.
It really is that hackers outnumber developers and that developers have to be perfect all the time and one of the hackers just needs to get lucky once. Hackers are often more like specialized technicians that are skilled in a narrow range, not a skilled engineer that can design a system from scratch. And then there are the kiddies.
I&T (Score:3, Insightful)
I agree, to a point.
Haphazard destruction doesn't generally require skill. On the other hand, speaking as someone with Integration & Test experience, the deliberate breaking of something that is engineered to be resistant in that manner does require skill.
Constructive destruction, I guess is what I'm referring to. Sticking RAM in an acid solution could conceivably cause BSODs, but that doesn't mean you've ha
False analogy (Score:5, Insightful)
Your car analogy would be good if we were talking about computer code -- it takes a lot more skill to write some good code than to mess it up (in textual form). But that's not what we're talking about here.
We're talking about circumvention of security, often known as "breaking" it; but that break (to circumvent protection) is a very conceptually different break than your car example (to render nonfunctional).
Finding exploits like this takes time, intelligence, and often understanding of the software in question. Especially in a well-crafted system, you have to know how the system works in order to circumvent it.
Re:False analogy (Score:3, Insightful)
Huh? understanding a system designed to be secure well enough to circumvent its security actually requires a better understanding than the designer's. You have not only to know the system, but to go further than the designer went in order to find a way in overlooked by an active attempt to eliminate vulnerabilities.
Breaking into a system not designed to be secure, on the other hand
I'm stunned.... (Score:3, Funny)
That's the furthest away from the topic in the shortest amount of time I've ever seen. Bravo!
Re:Seriously (Score:4, Insightful)
There are some genuinely skilled crackers out there, but they're fairly few and far between. I maintain a bunch of computers, and most of them deal with a cracking attempt a day. Let me give you a quick log extract:
Feb 21 03:22:56 <hostname> sshd[25243]: Invalid user firebird from <IP removed>
Feb 21 03:22:57 <hostname> sshd[25245]: Invalid user art from <IP removed>
Feb 21 03:22:59 <hostname> sshd[25247]: Invalid user manu from <IP removed>
Feb 21 03:23:00 <hostname> sshd[25249]: Invalid user peru from <IP removed>
Feb 21 03:23:02 <hostname> sshd[25251]: Invalid user contra from <IP removed>
Feb 21 03:23:03 <hostname> sshd[25253]: Invalid user fbi from <IP removed>
Feb 21 03:23:05 <hostname> sshd[25255]: Invalid user melanie from <IP removed>
That's just someone trying random username/password combinations and hoping. Eventually, they'll find somewhere with looser security, and get in, but that doesn't make them skilled, it makes them annoyingly persistant.
Don't get me wrong, this OS X exploit is actually fairly interesting, but most crackers have just enough knowledge to be dangerous, and not enough to use it wisely.
If you want impressive, have you considered the people securing these things? They don't have to find just one security hole, they have to find them all. They have to know every way someone might try breaking the system, and then some...
Re:Apple, innovative? (Score:3, Insightful)
How did you reach that conclussion*?
Is everyone who mods down serial trolls these days an Apple zealot?
*see GP
Also works in Mail.app (Score:5, Informative)
You can test this by downloading this harmless exmaple:
http://www.heise.de/security/dienste/browsercheck
...and sending the resulting JPG to yourself in Mail.app.
This is rooted in something that has been true about Mac OS in general for over 22 years, which is that any file or document - including executables - can have any icon. Other elements of the OS (such as the Get Info window) properly identify it as a Terminal document (shell script), and show that it is opened with Terminal, but most users won't see or understand this.
I'd expect a security update that addresses this *very* soon. This is a bad one.
Security fix out allready! (Score:2, Funny)
Security fix has been out for some time.
Available here [ubuntu.com]
Re:Security fix out allready! (Score:2)
Sign me up!
And seriously, this isn't any bigger than any number of social engineering security vulnerabilities that take advantage of some flaw or shortcoming in any other OS...
Re:Security fix out allready! (Score:5, Insightful)
Granted, if I try to change firewall settings or affect anything outside of your account's permissions you will be prompted for a password. But I could still delete or corrupt all your files, change your bookmarks, send email to your friends and family with an exploit and try to IM your buddies with it - I just have to choose a well-crafted malware.
I'd say this is a potentially evil hole. I just had my wife and kids change their default settings (I'd always had mine disabled - never thought to change my family's). I think, though that this one will also be quickly and simply patched. And really, the more "benign" wake-up calls Mac users get the better protected they will be and the more difficult it will be for any malware to gain traction.
Re:Security fix out allready! (Score:5, Insightful)
Since we've gone through the whole "download safe files" business a year ago, and Apple provided a prompt fix, and, additionally, since this is just Safari's executable-recognition code missing this because the shell script is malformed (i.e., missing the shebang), I expect a fix soon.
I was speaking to the social engineering aspect of this, since the automated aspect of this is so easy to mitigate, has already been addressed in one form a year ago, and I'm assuming will be quickly patched, leaving only the social engineering aspect to deal with. Which, once again, is no more or less serious than any social engineering exploit on any other platform.
Also, in case you hadn't noticed, getting a user to visit a web site is still a social engineering principle. Whether it's double clicking a file or tricking a user to view a web site, it's still "social engineering". What makes this unique is that Safari, in its default state, could potentially download a file and execute a shell script without user interaction. That's a Bad Thing. But since we've already dealt with this a year ago and missing malformed shell scripts was apparently an oversight, I expect this to be fixed soon.
Once fixed (or, in the interim, a single box unchecked) every other aspect of this just becomes tricking the user to click something.
And as we all know, that can happen on any platform.
In other words, this isn't a flaw that is endemic or inherent to any fundamental functionality; by all rights this whole issue was intended to be "fixed" a year ago, but it appears Apple missed malformed shell scripts marked as executable. Oops. So, that will be fixed, and everything else left is social engineering.
This isn't the first time a "view a webpage and something will download that can run without user interaction" exploit has happened on Mac OS X. But I'm sure the press will make a HUGE deal of this one, even though the previous two "viruses" discovered this week are *pure* social engineering, utterly useless, and the vulnerability that one used had even been patched since June 2005 and only affected Mac OS X 10.4.0.
I fully expect this to be the beginning of attacks on Mac OS X as "just as insecure as Windows" in earnest in the mainstream press, and also for people to completely misunderstand and believe it's related to the x86 transition. Yay.
Re:Security fix out allready! (Score:5, Insightful)
I think the lesson to be learned is that there is no such thing as a "safe" file type. Zip files can be auto-executed, image files can be run through scripting interpreters, malformed images can create buffer overflows in parsers...
We've seen security updates on Windows, Mac and Linux for GIF, PNG, JPEG and TIFF libraries.
Shell scripts are nothing but executable text files.
The solution, I suspect, is to simply not auto-open *anything* that isn't handled by the downloading app itself. Process whatever transfer encoding, but if the file is a disk image, wait for the user to open it. If it's a StuffIt or Zip archive, wait for the user to open it. If it's a video clip, and it's not playing in the browser, wait for the user to open it.
Sure, it removes a little convenience, but in the long run Apple might be better off disabling and then removing this option entirely.
The lesson should have been learned a year ago. (Score:3, Informative)
The solution, I suspect, is to simply not auto-open *anything* that isn't handled by the downloading app itself.
Or by a plugin designed to work with the downloading app, that is intended
Re:Security fix out allready! (Score:3, Interesting)
Re:Security fix out allready! (Score:3, Informative)
Um, not you're not - or you wouldn't have written in your original post:
This vulnerability has nothing to do with icons.
OK - I guess its true that you're aware now you've read other posters detailing how this works.
Also, in case you hadn't noticed, getting a user to visit a
Re:Security fix out allready! (Score:3, Insightful)
The vulnerability *I* was describing, i.e., the one that worked in Mail.app with this malformed-shell-script- masqerading-as-something-else, is a changed icon/social engineering trick. Albeit one that, in the example of Mail.app, one that a lot of people could possibly fall for, since Mail identifies it as a "JPEG Image", it has the correct icon, etc.; but by the time the user
This IS a bad one (Score:5, Insightful)
(Usual disclaimer: I use a unix>windows mix at work, mac at home, and use primarily firefox on all three).
People need to learn techniques to lock down their boxes - different OS are not all equally vulnerable, but are all vulnerable.
Re:This IS a bad one (Score:5, Insightful)
Re:This IS a bad one (Score:3, Informative)
No it is not a bug, its an implementation error.
No application on a computer should run downloaded code without human intervention.
Javascript is fairly benign. HTML is fairly benign.
"Autorun" in any variety is going to hurt people, See: http://www.google.com/search?client=safari&rls=en& q=windows+autorun+vulnerability&ie=UTF-8&oe=UTF-8 [google.com]
What about vbscripting? See: http://www.google.com/search?client=safari&rls=en& q=windows+vbscript+vulnerabil [google.com]
Re:This IS a bad one (Score:5, Informative)
The problem occurs when you have a shell script without the shebang line, and it's given Type/Creator codes so that it will open in Terminal.app (which will happily execute shell script without a shebang line, in the user's default shell). The name is unimportant; the only purpose it would serve is to make the user more likely to click on it on the web page. Which, as other people have pointed out, isn't really necessary since the file could be set to download automatically by the page. Clicking a link ON the page isn't necessarily required.
Re:Also works in Mail.app (Score:5, Informative)
I then unzipped the file and had a look at it in the Column view of the Finder, at this stage a normal jpeg would have been previewed, but the Finder had the file listed as "Terminal Application", but I think that most Mac users tend to use List or Icon view though, which would force them to open the file, activating it.
I then emailed myself the file with Mail.app 1.3.11 (In 10.3.9) and after the receiving the email I was warned that "Heise.jpg is an Application and could contain viruses, etc". after I attempted to save the attachment - It also did not preview in the mail message (Obviously)
Seems that this type of vulnerability is most likely to affect mid-level users who are somewhat reckless with their clicking and think they know better than new users who read and "cancel" every message box for fear of breaking their computers or advanced users who realize at a glance that the
Re:Also works in Mail.app (Score:3, Insightful)
Good news (Score:2)
It's inevitable though that there will be a major OSX infection, so it's time for Mac users to get more conscious of this stuff.
Oh, and more $$$ for the anti-virus guys I guess.
Re:Good news (Score:4, Funny)
"Pshaw! OS X will seamlessly update my applications wirelessly while I brew and sip my moca-latte, all with real time AJAX and SOAP requests over https with COCA SVG Widget bindings.
Mac users do not suffer from the contagions of the common masses."
Workaround: Camino (Score:5, Informative)
Get Camino here [caminobrowser.org]. Camino is an OS X native browser using the gecko rendering engine. Looks better than Safari, is faster than Safari, and apparently is more secure than Safari. Plus the security is more easily tunable.
Most Mac users have heard of it by now, but I'm just giving them another plug because it kicks ass.
Re:Workaround: Camino (Score:2)
Hate to reply with possible FUD, but I have honestly resisted using Camino due to the whole plug-in situation. Things like AdBlock/Filterset.G, NukeAnything, Tabbrowser Prferences, and FasterFox(!) really make FireFox much more usable/safe than any other browser out there (Opera was decent at v8.0, but I haven't really tried it since). How is the extension situation with Camino these days?
Re:Workaround: Camino (Score:2)
Re:Workaround: Camino (Score:2)
Re:Workaround: Camino (Score:2)
Re:Workaround: Camino (Score:2)
Re:Workaround: Camino (Score:5, Informative)
I don't know what the evidence for this claim is, but my (warm app, cold cache) tests on a few sites showed Camino to range from similar to slower than Safari.
and apparently is more secure than Safari.
Read the Secunia article [secunia.com] - this isn't a Safari security hole, it's an underlying platform issue and can be exploited in other ways.
Besides, the Mozilla family browsers have had their share of security holes.
Transcript of recent telephone phone conversation (Score:4, Funny)
*RING*
Jobs: Hello?
Gates: BWAHAHAHAHA! PWNED!!!!
Jobs: Goddamnit, Bill, I told you to stop calling!
Re:Transcript of recent telephone phone conversati (Score:2)
Just disable auto-opening files... (Score:5, Informative)
So just live without automatic file opening for the time being, and you're safe.
Re:Just disable auto-opening files... (Score:4, Informative)
According to Ars Technica [arstechnica.com]:
Protect yourself in one click (Score:5, Informative)
Re:Protect yourself in one click (Score:2)
Re:Protect yourself in one click (Score:2, Informative)
Re:Protect yourself in one click (Score:2)
Re:Protect yourself in one click (Score:5, Interesting)
I did this years ago.
Can someone remind me what is the point of a browser allowing "driveby downloads" and automatically launching the content of the download?
Safari has a nice download manager that lists the most recent downloads, and by simply double clicking on the one you trust and want to view is up to you.
This is at least over a 1 year old issue: http://www.net-security.org/vuln.php?id=3461 [net-security.org]
Is it too much to ask for normal users to double click on a file to launch it? This is what we used to do, and still do with email, ftp, removable media, networked drives, everything. What is the point of a driveby download and launch?
Re:Protect yourself in one click (Score:3, Insightful)
IMNSHO, the expected behavior of Secunia's demo should be QuickTime complaining
Seems to work with any browser (Score:5, Informative)
The only difference is that the default behavior in Safari is to automatically open downloaded files of certain trusted types.
Who wouldn't try clicking on a movie icon? I would think that most people would.
Re:Seems to work with any browser (Score:2)
It doesnt matter what OS you use (zOS, Linux, windows, Mac, etc), you run the risk of damaging those parts the user has access to if you run things downloaded from random websites.
It does require that you open the zip file, (Score:3, Insightful)
I have not tried it in Safari with "open safe downloads" off, however I just tried it again in Firefox and if you have it set to automatically open zip files and then you open the movie file, the calculator does appear. (my system is up to date according to Software Update too.
I think the real problem is that it's possible to disguise an attack as a quicktime
OS X 10.4.5 (Score:3, Interesting)
I'm running 10.4.5 with Safari 2.0.3. Looks like not everyone is vulnerable.
Re:OS X 10.4.5 (Score:2)
Re:OS X 10.4.5 (Score:2, Funny)
Re:OS X 10.4.5 (Score:5, Funny)
This sounds familiar (Score:2)
We shouldn't be surprised at things like this popping up, OS X is getting more popular/press, so they've beco
fsck'ing "open safe files" option (Score:2)
I honestly think that Jobs really bought into his own RDF with this one.
You can't tell me that after Win98 & IE4 + 8 years... anyone still believes that bypassing security for "features" is a good idea on as hostile a network as the internet.
Esp. with someone with as seemingly high a clue-factor as Jobs...
I just turned off the feature on my Safari, and sent an email to my wife to do the same on her powerbook.
Mac users: welcome to 2001 (Score:5, Funny)
inneresting (Score:2)
This is just like a .jpg.exe (Score:5, Interesting)
So the guys in apple who had the __MACOSX part to zip files didn't communicate that to the Safari folks. Communication gaps happen, but this is gross oversight in a company which claims to sell their software for a premium because it is cool (and well-tested UNIX background).
Shell vulnerabilities seem to be the entry point usually, seeing the firefox shell:// that was recently discovered... Integration comes with its own sweet price.
There is no totally safe software. (Score:2, Insightful)
There are inherently safe practices... (Score:3, Insightful)
Passing an unsafe file (ALL files recieved from an unsafe source are unsafe) to an API designed to allow dangerous things (LaunchServices is how many applications run their own components, it has to be able to do dangerous things) is an inherently unsafe practice. It should never be followed.
Maintaining a separate registry of applications that are designed to accept unsafe files (saf
Rocket (Score:2)
2. Safari must allow expanding of zip file
3. Zip app must allow executing of unzipped file (this is not normal)
4. Normally, the file will appear on the desktop, without being executed. It does have a movie icon, but for those of us who always pre-watch movies and what have you in a Finder column window, this doesn't really present a problem; it says Terminal Document below the movie icon (and no one in their right mind would zip a movie anyway, it's a bit like those pornmovie.exe y
System should be safe (Score:5, Informative)
Someone correct me if I'm wrong, but this exploit can only affect items that the user has rights to. If a script were written to make changes to the system, OSX should prompt you for your password, right?
Re:System should be safe (Score:5, Insightful)
Like ~/Documents/ where you're encouraged to store pretty much everything you make with your machine.
Or ~/Pictures/ where iPhoto keeps everything it loads up.
Or ~/Music/ where iTunes puts all your music.
Or wherever the hell iMovie keeps what you build with it - probably either ~/Movies/ or ~/Documents/
Or wherever the hell GarageBand keeps its work.
Sure, the machine still boots. But if a script does rm -rf ~*.* you're kinda fucked. Why is it that Slashdotters always say 'oh, this exploit just affects userland, no big deal'?
Re:System should be safe (Score:3, Insightful)
The history of that school of thought is that under real multi-user systems if one non-root account gets hosed everyone else can continue on with no ill effects.
Anyway I'm beyond shocked that t
Re:System should be safe (Score:3, Insightful)
Why is it that most people who trot out that line always assume that because a windows exploit can take down their OS, it isn't going to trash their home directory as well?
Also, it's a hell of a lot easier to restore a single user's files if the rest of the OS is still intact.
If your OS gets pwn3d, you can't trust it. At all. You know the r00tkit tech that Sony has recently been grilled about? It's called a r00tkit a
But that doesn't require root access. (Score:3, Insightful)
But they don't need root to get control of your machine and turn it into a spambot...
All they need is a place to hide an executable that you'll run every time you log in.
Like, oh, dozens of places beneath ~/Library/
Re:System should be safe (Score:3, Insightful)
It may not be able to make itself last through rebootings, but you're not supposed to have to reboot OS X very often.
Re:System should be safe (Score:3, Insightful)
Interesting (Score:5, Funny)
Two Words: (Score:5, Insightful)
Hey Safari, Internet Explorer 4 called... (Score:2)
Tried on Windows (Score:4, Funny)
Doesn't work in 10.4.1 (Score:2)
At least there's one way.. (Score:3, Funny)
Yep, this is a genuinely bad bug (Score:5, Informative)
Explanation: Apple recognizes a particular folder within a zip archive as resource forks. This way you can correctly upload/download old-style apps and/or OSX metadata. The latter feature is where the problem occurs.
If you take a shell script, rename it to a "safe" file extension (such as mov, jpg, etc), then change its metadata (aka the "Open With..." setting) to Terminal.app instead of the expected default application, you now have a shell script that looks like an ordinary media file.
If you then use OSX built-in BOMarchive command, you have a zipped shell script that looks like a "safe" download.
End result: arbitrary shell script execution (under OSX default settings) upon visiting a malicious URL.
Conclusion: remote metadata should not be trusted. This bug would not occur if downloaded files could only belong to their default app.
OSX hole or Safari hole? (Score:2)
Why isn't Secunia Being Flamed Here (Score:5, Interesting)
Re:Why isn't Secunia Being Flamed Here (Score:3, Informative)
NOT terminal, NOT a bug. (Score:3, Informative)
Terminal.app does no such thing. It simply passes on whatever you give it to
It's not a bug in
The "bug" is a pair of known design flaws in Safari that Apple should have fixed two years ago, along with a change in the unzipper that
My credit card was "compromised" while using Safar (Score:5, Funny)
Most recently, a $300 charge appeared on my statement after visiting this page. [apple.com]
Earth to Apple: THERE ARE NO SAFE FILES! (Score:3, Interesting)
"Open Safe Files After Downloading" is inherently risky. No files should be considered safe. The user should always make an explicit request to open any file not handled by the browser itself. Approving an action requested by a potential attacker is not making an explicit request: even if Safari detected the executable and popped up a dialog it would still not be good enough to prevent many people from reflexively approving it.
In addition, automatic execution or interpretation by a general purpose scripting language of any files in an archive, removable media, disk image, or any other potentially untrusted container is inherently risky. Executing code, using applications found in the volume as handlers, or otherwise using them, should be deferred until the user has explicitly requested the code be run, installed, or used.
This should be such a fundamental principle of secure software design that it shouldn't have even occurred to Apple not to follow it.
Just being less insecure than Microsoft is not enough. One might as well laud smallpox as being less deadly than Ebola.
(and... I told you so)
Inaccurate to say "just by visiting" a web site (Score:3, Insightful)
The real problem isn't Safari or Mail.app, it's LaunchServices which needs to smarten up Real Soon Now.
This is good news (Score:5, Insightful)
Re:Totally OT Question (Score:3, Informative)
There's also Camino if you want something that looks native. It's gecko based, but doesn't have the extendibility.
Re:Totally OT Question (Score:3, Informative)
Re:Odd... (Score:3, Insightful)
He who humbles themselves shall be exhulted he who exhults them selves shal be humbled.
This is true in tech as well.
If you feel that your computer is involnerable to hacks you will get hack eventually. This is true for Linux, Solaris, even OpenBSD users. The more secure you say it is the more people will want to find a way to break in. This is espectially true for OS X users because they like to glote on how secure their OS is. But there are a lot of people still feel bitter with the IB
Re:Odd... (Score:5, Funny)
Re: (Score:3, Funny)
Re:Only affected at user level? (Score:4, Insightful)
Re: (Score:2)
Re:Safe default settings (Score:5, Interesting)
Re:how bad is it really? (Score:5, Informative)
Not bad unless you are a complete frigging idiot! (Score:3, Insightful)
It downloaded the file.
To get it to unzip I had to double-click on it.
To get it to execute I had to double click on it.
According to This article [techtree.com]
Safari also unpacks ZIP archives, and displays the documents inside if they are "safe". In the event active content is found in the archive, user confirmation is requested.
Typically shell scripts begin with a "shebang line" such as "#!/bin/bash" to ind
Solution found! (Score:3, Insightful)
Re:Not bad unless you are a complete frigging idio (Score:3, Informative)
I'm running Safari 2.0.3(417.8) with the "Open safe files after downloading" option checked on an Administrative account. When I click on the link it downloaded, unzipped and executed by itself.
I then created a brand new test account with no admin priv's and trie
Re:Not bad unless you are a complete frigging idio (Score:3, Insightful)
Then you have a nonstandard configuration (have you installed a different unzipper or otherwise changed the handling of zip files?), or you didn't actually have "Open Safe Files" turned on.
Re:that tears it! (Score:3, Funny)
Here's some information. (Score:5, Insightful)
It's possible for a website to initiate a download.
and have the automatic "safe file open" option turned on
Which is on by default, therefore it can be used to propogate worms.
Files that don't match their extension should be handled.
WRONG! There's three things that MUST be fixed.
Open safe files after downloading SHOULD NOT BE ON BY DEFAULT EVEN IF IT IS AN OPTION.
Zip files and other containers SHOULD NOT BE TREATED AS SAFE FILES EVEN IF IT IS ON.
Unpackers MUST NOT AUTOMATICALLY OPEN ANY FILES IN THE CONTENTS OF A PACKAGE.
Both Apple's unzipper (attacked in this case) and stuffit expander violate this last in different ways.
Re:Remote meta-data? (Score:4, Informative)
No, that is no problem at all. The problem is that two applications (Safari and Finder) used different code to decide whether this is a script or not. Safari thought it was a JPEG file. That would have been no problem at all if the Finder had agreed and had asked Photoshop to open that JPEG file. The problem was that the Finder looked at the same file with the same metadata and came to a different conclusion, believing that the same file was a shell script.
Re:This IS Bad.. (Score:3, Insightful)
You're assuming that a worm's only goal is to delete everything it can and you'll notice immediately. How about a worm that ftps all your private files to a server? Would you notice?
How about the fact that the default user in OSX can modify everything in Applications. iTunes could be replaced with a script that did something malicious, then ran iTunes.. would yo