ie8 fix
madison

Zero Day

Ryan Naraine, Emil Protalinski and Dancho Danchev

Adobe PDF exploits using signed certificates, bypasses ASLR/DEP

By | September 9, 2010, 11:54am PDT

Summary: The zero-day attacks against Adobe PDF Reader/Acrobat includes the use of clever techniques to bypass anti-exploit roadblocks in Microsoft’s newest operating systems and a signed digital certificate belonging to a U.S. credit union.

The zero-day attacks against Adobe PDF Reader/Acrobat includes the use of clever techniques to bypass anti-exploit roadblocks in Microsoft’s newest operating systems and a signed digital certificate belonging to a U.S. credit union.

The attacks, which use booby-trapped PDF documents to exploit an unpatched vulnerability in Adobe Reader/Acrobat, first appeared as an e-mail attachment titled “Golf Clinic.pdf” that promises golf tips from instructor David Leadbetter.

New Adobe PDF zero-day under attack ]

follow Ryan Naraine on twitter
If the target opened the document, the PDF file crashes before immediately opening a decoy file with the same name (in lower case) which gets dropped in user profile Application Data, according to Contagio Malware Dump, a site that tracks malicious spam and web activity.

A downloader file gets dropped  in user %tmp% directory downloads winhelp32.exe, which creates a connection to academyhouse.us.

According to Roel Schouwenberg, a senior virus researcher at Kaspersky Lab (important disclosure) , the exploit uses the ROP (return oriented programming) technique to bypass the ASLR and DEP mitigation technologies in Windows Vista and 7.

Dino Dai Zovi, a researcher who has publicly discussed details of return-oriented programming and the ways in which it can be used to exploit vulnerabilities, described the PDF attack as “pretty impressive” because of the complex techniques used to bypass Windows defenses.

Kaspersky’s Schouwenberg also discovered that the malware attack drops a file that is digitally signed with a valid signature from Vantage Credit Union, a US-based Credit Union.

Schouwenberg writes:

This means that the cybercriminals must have got their hands on the private certificate. Remind you of anything? If you say Stuxnet (where compromised Realtek and JMicron certificates were used to sign files) then we’re clearly thinking on the same lines.

It’ll be interesting to see if Stuxnet has started a trend or if these cases are just a flukey coincidence. I suspect they’re not - I think the use of valid, stolen certificates to sign malware will really take off in 2011.

Adobe has released an alert to confirm the vulnerability and active attacks and notes that there are no pre-partch mitigation guidance to thwart these attacks.

End users worried about falling victim to these attacks should consider using an alternative software product to view PDF files.

Kick off your day with ZDNet's daily e-mail newsletter. It's the freshest tech news and opinion, served hot. Get it.

Topics

Ryan Naraine is a journalist and social media enthusiast specializing in Internet and computer security issues.

Disclosure

Ryan Naraine

The most important disclosure is of my employment with Kaspersky Lab as a member of the global research and analysis team. Kaspersky Lab is a global company specializing in anti-malware and secure content management technologies. I do not own stocks or other investments in any technology company.

Biography

Ryan Naraine

Ryan Naraine is a journalist and social media enthusiast specializing in Internet and computer security issues. He is currently security evangelist at Kaspersky Lab, an anti-malware company with operations around the globe. He is taking a leadership role in developing the company's online community initiative around secure content management technologies.

Prior to joining Kaspersky Lab, Ryan was Editor-at-Large/Security at eWEEK, leading the magazine's and Web site's coverage of Internet and computer security issues and managing the popular SecurityWatch blog, covering the daily threats, vulnerabilities and IT security technologies. He also covered IT security, hacker attacks and secure content management topics for Jupiter Media's internetnetnews.com.

Ryan can be reached at naraine SHIFT 2 gmail.com. For daily updates on Ryan's activities, follow him on Twitter.

Related Discussions on TechRepublic

Did you know you can take part in these discussions with your ZDNet membership?
33
Comments

Join the conversation!

Just In

RE: Adobe PDF exploits using signed certificates, bypasses ASLR/DEP
DanielB 13th Sep 2010
@Dietrich

It's the coders you moron. Most of these 3rd party software developers don't code basic operations for security.

I think we all agree that users *shouldn't* run their compy's in admin/root space all the time. It's just asking for it.

However, many coder's don't support that, and effectively force users to run as Admin becuase they're lazy or stupid.

Mozilla still won't let you run an update from user space, by simply asking for the admin pw, as you can from *nix or OSX.

Whose fault is that, if the user is doing the right thing, and the OS supports temporary priv elevations like sudo.

Quit being an ignorant fanboi Dietrich.
... new Milla Jovovich photos perhaps...
0 Votes
+ -
from a link I saw in my spam box silly and yep, was hit. sad Dammit, when will I learn?
@klumper : When will you learn is right! It is ludicrous to even view the contents of a spam or any possibly malicious code. If you still cannot tell badmail from goodmail just by looking at the sender and subject lines, you need to get offline; you're a danger to yourself and to others.
There are only 2 logical things to do with badmail; deliete it sight unseen, or learn how to report it safely and keep those slobs on the many blocklists around the world.

I also see absolutely no reason for you to have posted your ignorance of the subject as you have just done; you'd be a lot better off spending the time learning how to avoid crap like that.
0 Votes
+ -
Wait till you see what I managed to do later
klumper Updated - 10th Sep 2010
@twaynesdomain

Look below. plain

Sometimes these cursed fingers of mine get a-clickin' and won't stop, like they're inhabited by tiny chupacabras. sad
0 Votes
+ -
There is a key component that all systems have that continues to be shamefully exploited. The curiosity and naivety of general users.

Back away from the that mouse button. Do not click on it.

Just like your mama taught you. Do not talk to strangers.

Do be clicking on no strange emails or pop-ups. Delete spam, ignore pop-ups no matter how interesting they look.

Then, go check a legit source on a topic you need or want to read about.
@daniel.pereznet

Funny, my mother didn't teach me that, because she knew that strangers were NOT the real danger but people who I was introduced to by her. Seriously, how often have you heard of a COMPLETE stranger snatching a child?

Not often, it's usually someone with some kind of connection to the family, even if it's only meeting the person in question at a block party.
0 Votes
+ -
Thank you for illustrating the current threat dyanmics inherent from the growth of Social Media. Most of us learned these "don't follow links from strangers" lessons long ago on the internet. Then came the myriad of ways to stay connected from your friends. The threat vectors aren't just strangers anymore, and the badguys pose as our friends making users far more likely to trust something. Blaming the user isn't a panacea folks, since the threats have become more sophisticated, and less coarse and identifible each iteration.
The solution is going to have to come in the form of offense soon, because reactive defense just isn't cutting it and software developers still code for security as an afterthought.

Right now, I don't even want to touch any Adobe products after all these Flash and PDF vulnerabilities.
0 Votes
+ -
@daniel.pereznet
Back away from the that mouse button. Do not click on it.

Yeah, easy for you to say. You have self restraint. plain
0 Votes
+ -
I think the real person to blame
Joe_Raby Updated - 9th Sep 2010
...is the companies whose digital certificates are taken from. Clearly they aren't locking down systems that have access to the digital certificates in raw form.

It reminds me of the issues of hardware makers that include viruses on devices.

Companies should know better than to let Jim-Bob or Kim Dong have free access to the Internet on a business-critical machine that has no business with an Internet connection in the first place. They have to ask themselves: "do they need Internet access to do their job on this computer?". If the answer is no, cut the bloody cord! If the answer is "no, but [insert excuse here]", they need to step aside and hire someone that knows what they're doing in IT.
@Joe_Raby

Little problem: most of those people DO need internet access, so you cannot just 'cut the damned cord'..... for god's sake man, get REAL here and stop spouting bull!
@Lerianis10 /The only bull-spouting I've seen here is yours. Myopic narcissist comes to mind, in fact.
@Joe_Raby and the biggest offenders, are the execs and CEO's who don't want to follow security practices or have their computers restricted.

Yeah, go tell 'em what's what, tough guy. Let me know how that works out for you...

Why do you think the malicious pdf's were oriented at golfers, genius? Not the rank and file, in this economy.
0 Votes
+ -
No worries here.
Dietrich T. Schmitz, ~ Your Linux Advocate Updated - 9th Sep 2010
Windows Folks must accept the fact that Windows security is broken.
Windows offers no Linux LSM equivalent to protect users against unintended side-effects of 3rd-party Apps.

Side-effects is a euphemism for exploits, folks.

Anyone running Ubuntu 10.04 will be happy to know their default PDF viewer is Evince.

Just so happens, Ubuntu saw fit to place Evince in an AppArmor LSM profile.

So, Ubuntu lovers, no worries here.

Ubuntu Linux: The safest operating system on the planet.

I stake my reputation on it.
0 Votes
+ -
was broken some time ago, so too have Windows users discovered the same thing.

But then, data has shown that not many Linux users are golfers, so the exploit will not effect them as it will not be opened.
plain
@Mister Spock
well said there sir
security is broken as soon as a human writes the code. ignorant people are the third worst thing on the internet, beaten only by ignorant people who think they aren't, and trolls.
@Dietrich T. Schmitz, Your Linux Advocate

Lol... So ultimately, you're saying that Ubuntu offers an alternative to Adobe as a standard. Since Adobe isn't standard on MS, then Microsoft users should be happy to know there are a plethora of options for their PDF files!

Microsoft Windows...the most compatible Operating System around...

I stake Bill Gates' reputation as one of the richest men in the world on it!

Happy Posting!!
0 Votes
+ -
Missing the point
Dietrich T. Schmitz, ~ Your Linux Advocate Updated - 9th Sep 2010
@G-Systems
LSM was created to provide a mandatory access control system that not only polices the 'App' but also the 'kernel'.

Linux can't protect against unintended side-effects. It is LSM that provides the ability to profile any 3rd-party App to specify in a very fine granular way what actions are taken by the App and the kernel on behalf of the App.

There is no notion of an external LSM mechanism in Windows 7.

That leaves users and Admins with few or no options.
In this story the author concludes:

"End users worried about falling victim to these attacks should consider using an alternative software product to view PDF files."

That is not a security remedy. It is an admission to the fact that Windows does not offer an LSM equivalent to sandbox Apps.

Yet, Microsoft has seen fit to 'feather their own nest' in writing Office 2010 with sandboxing.

That is more than a bit troubling and if I were an Admin seeing these daily zero-day reports, I'd be asking why can't Microsoft provide a mechanism like LSM so we can at least sandbox our Apps.

That would alleviate the immediate need for continual fire drills to mitigate these zero-day threats, because with a well-defined LSM profile any unintended side-effect, e.g., exploit, is stopped cold. Admins and users alike using Ubuntu need not worry even if a zero-day defect is published or discovered because it will not have mattered with LSM profiles in place and the defects will be patched in due course by Canonical.

Therein lies the core difference between Windows and Linux LSM.

Be safe with Ubuntu Linux.
I stake my reputation on it.
@G-Systems
I think you are forgetting the fact that the first choice Windows user get when they need to open a *.pdf, is Adobes reader.
Other than that; you are right : there are safer readers for Windows.
@Dietrich T. Schmitz, Your Linux Advocate
Shut up, will you? if you can't afford Windows then stick with that ugly piece of Linux crap
0 Votes
+ -
RE: Adobe PDF exploits using signed certificates, bypasses ASLR/DEP
Dietrich T. Schmitz, ~ Your Linux Advocate 9th Sep 2010
@shellcodes_coder
Is that the best you can offer? I can afford Windows, but I run it as a VM on a base system of Ubuntu, and it runs in 'immutable' mode.

You can draw your own conclusions from that.
Try though to step back and be objective. Personalizations only diminish your position.
0 Votes
+ -
Re; if you can't afford Windows . . .
hkommedal 10th Sep 2010
@shellcodes_coder
That sounds a bit daft !
I do have Windows , but I do not use it very much.
So I could afford it and I did buy it.
I still use Linux (openSuSE) most of the time (99.5% of the time or more).

So I do have Windows, but choose Linux over Windows, despite the fact that I have been using windows since 1991 and I am therefore used to Windows.

I can assure you that I find more "crap" in the Windows system than the Suse Linux system.

Apart from that: DTS is quite annoying with the same statement over and over again.
@Dietrich T. Schmitz, Your Linux Advocate : No, you are not an advocate; you are an intentionally ignorant fanatic who can't see reality. Linux is full of holes and if it ever gets a respectable market share, you'll learn all about them. If you haven't been keeping up with LInux tech papers, you really should.
oops i already posted. please ignore my failed posting skills
@Dietrich T. Schmitz, Your Linux Advocate

ubuntu's pretty good. it provides above-par protection for users. it uses tools such as LSM, the-very-idea-of-*nix-environments-being-permissions-based-ness, firewalls (wait, never mind, its permissive by default), SELinux (oops, nevermind again). anyways, it provides great protection for users, and does a great job of keep users away from many of the security pitfalls windows users face.

but, have you heard of the new linux distro? its called ImagineLinux. it is the strongest, most secure system in the world. it's lightning fast, never crashes, and is hardened against every attack out there. there are no updates, because it is a perfect system written by giant mythical god-like robot spiders; no imperfect human hands have soiled its perfection.

The one downside is that it is not compatible with x86, ppc, arm, or any other processor architecture. it will only run on virtual machines made of wild fantasy on a host system of unrealistic imagination.

as a linux user myself, i know that it is important to not get these two operating systems mixed up; i fear you may have let it slip. gotta be careful, don't want to sound like an apple fan
really sorry guys, is there a way to delete posts? i posted this 3 times by accident... anyways...
@Dietrich

It's the coders you moron. Most of these 3rd party software developers don't code basic operations for security.

I think we all agree that users *shouldn't* run their compy's in admin/root space all the time. It's just asking for it.

However, many coder's don't support that, and effectively force users to run as Admin becuase they're lazy or stupid.

Mozilla still won't let you run an update from user space, by simply asking for the admin pw, as you can from *nix or OSX.

Whose fault is that, if the user is doing the right thing, and the OS supports temporary priv elevations like sudo.

Quit being an ignorant fanboi Dietrich.
0 Votes
+ -
Ah crap
klumper Updated - 9th Sep 2010
Now I clicked on a "Here you have... Terry Jones Pastor" link, just out of curiosity, and am being rooted from but another direction! Who'd guess lightning could strike twice?

Unfortunately the two rooters - one from the Caucasus and the other from Nigeria - are engaged in pitched battle for my pooter's soul, so I have yet to determine what the ransom check will be. I made my way to the public library so I could write this. sad
@klumper

That's just funny... lol You're wild!

Happy Posting!!
0 Votes
+ -
10
Dietrich T. Schmitz, ~ Your Linux Advocate 9th Sep 2010
@klumper
Keep them coming. LOL.
0 Votes
+ -
Take a look at your screen...and see why Adobe
Narr vi Updated - 9th Sep 2010
For the moment of this crisis, I reviewed a current version and installed Sumatra, then redid all the ways browsers open pdfs. Fine.

Then I compared the results. Adobe Reader looks _much_ better. Fonts are clearer and much better defined in their details.

So Adobe is going back in as soon as this storm passes.

Sumatra is ok for quick reading, but Adobe is much better on the eyes, and thus for spending time with an article.

I also tried PDF-XChangeViewer, and it is worse than Sumatra, although you can adjust the 'font gamma'.

Because of the nature of their visibly lower contrast and fuzziness, I suspect Sumatra and Viewer may look better on a CRT, may be optimized only for that kind of screen.

I am using a laptop LCD screen, and here Adobe excels. Do you suppose that 'maybe', there is some sophisticated software in that so-called bloat? I think so, even if I think we wish now that they'd left some of the scripting and media tie-ins out.
0 Votes
+ -
Foxit Reader
Patanjali 9th Sep 2010
@Narr vi
Lightweight PDF reader. I got sick of the bloat of Adobe Reader and its viral update component.
0 Votes
+ -
I second that, but would go further
thx-1138_@... Updated - 10th Sep 2010
@Patanjali

For those that use IE8 as their primary browser of choice, switch to Foxit 4.1.x.x and you should be fine as IE8 operates by default in a sandbox.

For those Windows users that use alternative browsers to IE8 - and that includes IE7 or before - consider installing Sandboxie.

Benefits of Foxit 4.1.x.x: In all versions of Foxit in the 4.1.x.x series there is an inbuilt safe-usage mechanism that isolates and explicitly denies *.pdf files from communicating and accessing the Internet. To enable this in Foxit 4.1.x.x, simply open Foxit and in the toolbar navigate to: Tools -> Preferences .. a window should appear. Scroll down to 'Trust Manager' and click .. if it isn't already, tick the radio-box so that Safe Reading Mode is enabled. Next, just click on 'OK' and close Foxit.

Benefits of Sandboxie: Sandboxie is a free software that once installed enables a user to isolate (.. or sandbox) a program, file, or a process in a 'virtual box'. That is to say that it allows a user to run an item they are unsure of without adversely affecting the host system. When the user has finished they can simply delete the contents of the sandbox trivially.

Now, used together - that is, Sandboxie to isolate browser sessions and Foxit 4.1.x.x to read online and local PDF files .. then you get the idea of how much safer your user experience can be when accessing the Internet and, for that matter, local material you are unsure of.

(n.b. I don't work for either Foxit or the owners of Sandboxie .. so yeah, this is not a paid advertisement for the products: just a headsup for those that want an interim solution to this particular security vulnerability)

Sinceremente
@Patanjali, @thx-1138, thanks. Good thoughts from both.

Because of them, I tried the Foxit Reader again - had not because or previous bad luck with its lack of color management in printing, and recent comments indicated bloat and sneaky toolbar-adding.

Here's what I found:

- Foxit is trying not to be as obvious about their toolbar-adding, but they are still at it. If you don't watch the 'finished installing' screen very carefully, you'll get a toolabar. Also, there is an Ask.com searchbar embedded in Foxit - cleverly 'turned off' maybe because I specified to install in safe mode.

- Also, even in web-safe mode install, Javascript is turned on in Foxit.

- There's an array of bloat/addons/browser plugins, but at least they've made these separate downloads.

Then I looked at the screen. Well, at first Foxit looks a bit better than Sumatra etc.. They do have an LCD screen option, and it does work, plus was turned on automatically for my screen I think.

However, fonts don't look as clear as in Adobe Reader, and there was something else bothering me -- in a way, the sizing didn't look right.

I realized that what any but Adobe Reader had done was to throw away at least a very important level of font hinting. Thus the fonts don't even look like they are supposed to for their family, as they get smaller - and actually when they are at normal reading (i.e. 12 point or so) size!

This is important for readability, and it is important as far as the look we use fonts to give.

My take is, once again. Sumatra is a nice, clean, open-source alternative that I will keep on the machine for any intervals of un-thwarted attack on Adobe.

But in any other time, I will use Adobe's Reader, for it's very much better readability and accurate look.

Sandboxie - a good idea, actually. Have considered it, and not sure it works with favorite browsers, as I wouldn't use IE. But worth a look.

Regards to both,
narr vi

Join the conversation!

Formatting +
BB Codes - Note: HTML is not supported in forums
  • [b] Bold [/b]
  • [i] Italic [/i]
  • [u] Underline [/u]
  • [s] Strikethrough [/s]
  • [q] "Quote" [/q]
  • [ol][*] 1. Ordered List [/ol]
  • [ul][*] · Unordered List [/ul]
  • [pre] Preformat [/pre]
  • [quote] "Blockquote" [/quote]
ie8 fix
Click Here
ie8 fix

The best of ZDNet, delivered

ZDNet Newsletters

Get the best of ZDNet delivered straight to your inbox

Facebook Activity

White Papers, Webcasts, & Resources
ie8 fix
ie8 fix