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Stuxnet Questions and Answers (f-secure.com)
137 points by Garbage 3 days ago | 70 comments




16 points by rm-rf 3 days ago | link

The F-Secure Q&A is relatively free from speculation. That's unusual for this particular event.

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6 points by njharman 3 days ago | link

Stuxnet amazes me. My first tech job was (in part) installing anti-virus on every computer in the Univ KS Library system, 1989-90. MS-DOS days. I've been an avid watcher (not expert) of malware since. I've watched the Internet arrive and embedded computer/automation revolutions. This 20yr perspective brings me to the following conclusion.

Other than "jacking in" and other fluff Stuxnet does pretty much exactly the kinds of things that CyberPunk Sci-fi described a decade ago.

I flippin love living in the future.

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1 point by rm-rf 3 days ago | link

"Your computer is now stoned."

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2 points by adrianwaj 3 days ago | link

The Iranian regime is now stoned. How happy I am with Stuxnet.

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2 points by danbmil99 2 days ago | link

You'll be less happy when China uses the same techniques to destroy Google

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2 points by adrianwaj 2 days ago | link

Stuxnet is real. Your scenario is unrealistic.

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12 points by iuguy 3 days ago | link

This is quite possibly the best Q&A on Stuxnet I have seen. Kudos to F-Secure for not overhyping it.

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5 points by chris_l 3 days ago | link

This reads like a section from a sci-fi novel. Once more reality is catching up with cyberpunk.

I'd love to know what it's supposed to do when it reaches its target. Surely the creator would have had to have some sort of blueprints for the target system to successfully set it up to create more than collateral damage.

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17 points by humbledrone 3 days ago | link

I'm very curious about what it's supposed to do as well. I work with SCADA systems, and I can confirm that it would be difficult/impossible to tell without knowing exactly what system it's targeting. SCADA systems are often controlled by writing to "points," which typically have numeric addresses. So point 35 might control the valve position in one installation, but it could control something totally different in another. You'd need to know the layout of the targeted system to know what parameters are controlled by what points.

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2 points by joe_bleau 3 days ago | link

I'm under the (mistaken?) impression it uses the SCADA system to actually modify some of the low-level PLC library code. If so, I'd be looking for code likely to be used (by the actual plant PLC program) to stabilize a very high speed centrifuge (servo routines maybe), and introduce slight instabilities, or even better, excite a resonance.

"Hey, the VFDs are programmed to skip through this frequency band during the accel ramp to 25k RPM, but every once in a while they hickup and then the bearings rub. What's up with that?"

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3 points by borism 3 days ago | link

But messing with various points at different facilities in the same way can still be catastrophic.

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2 points by humbledrone 3 days ago | link

Very true. A simple "set everything to zero" approach would probably bring any facility to a halt (if not worse).

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2 points by sunburnt 3 days ago | link

Q: What does it do with Simatic? A: It modifies commands sent from the Windows computer to the PLC. One running on the PLC, it looks for a specific factory environment. If this is not found, it does nothing.

So it seems that there is one factory layout Stuxnet is looking for. I.e. it will know what point 35 is.

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2 points by borism 3 days ago | link

is it possible to determine which factory environment you're in? maybe it just tries the same combination in each and every one environment it gets to?

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1 point by uxp 2 days ago | link

Considering the size of the file, (and the fact I have not examined StuxNet), I'd assume that there is a good chance it has enough logic to determine which factory it is in by pure brute force.

If the main fan control gives a fairly standard reading, it shouldn't be too difficult figuring out what the particular factory it has infiltrated has wired that point to, for example.

Also, I haven't heard any definitives on what kind of factory this is targeting. I do know that there aren't many companies that develop and design high tech industrial facilities. Despite StuxNet having infected thousands (millions) of personal PCs, it really is only looking for maybe a few dozen or so in the world that are of the right type. Combine that with a low number of factory designs, and it could very well have a pre-determined database of how its intended targets are wired.

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4 points by TrevorJ 3 days ago | link

"Q: How could governments get something so complex right? A: Trick question. Nice. Next question."

That one caught me off guard.

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3 points by Tycho 3 days ago | link

It said the registry key Stuxnet plants to indicate whether a system is already infected has the value 19790509. Then it said an Iranian Jewish business man was executed on that date for spying. Also the home directory where the virus was originally compiled was called Myrtus. Which may contain another clue...

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8 points by eli 3 days ago | link

I'm not really buying this. You're making a lot of assumptions. That Iran is the target, that the number is a date, that the date refers to that particular event, etc.

The link between the word "Myrtus" and the Old Testament seems really strained. It's the name of a plant. It features prominently in Greek mythology -- maybe the Greeks did it?

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4 points by esspem 3 days ago | link

I don't think the link between old testament and myrtus is strained.

1) Eshter's born name is Hadassah, which means myrtle (http://en.wikipedia.org/wiki/Esther#Origin_and_meaning)

2) When Eshter asked the king if Jews can kill their enemies, king granted the permission (http://www.biblegateway.com/passage/?search=esther%208:11-8:...)

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7 points by theycallmemorty 3 days ago | link

Esther was also married to a Persian King.

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2 points by acqq 3 days ago | link

I also vote for a plant, as the second mentioned name is Guava and there is

"The Chilean Guava (Ugni molinae, also called Myrtus ugni or Eugenia ugni)"

see: http://www.strangewonderfulthings.com/206.htm

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2 points by eli 3 days ago | link

Good point. It could well be that the files are named after plants the same way some people name their servers after colors or smurfs or whatever.

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2 points by caf 2 days ago | link

In fact all Guavas are members of the Myrtle family.

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3 points by borism 3 days ago | link

He doesn't seem to make any assumptions to me. He states the known facts about it, that's all.

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4 points by anonanonanon 3 days ago | link

Chances are that if you pick a date at random, there will be some heinous crime that the Iranian regime has committed on that day. As to myrtus. Even if we assume that whoever did this knew that myrtus=hadas, very few Israelis who aren't biblical scholars would associate the name Hadas with queen Esther.

I would say that if this is the best we have, then it's pretty certain it's not the Israelis who did this.

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6 points by adrianwaj 3 days ago | link

Clues can be faked too.

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1 point by Tichy 3 days ago | link

Hm, this is no fun scavenger hunt for hackers. It's serious.

On the other hand, if you solve the puzzle, maybe you can sell your story to Hollywood.

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1 point by aufreak3 3 days ago | link

Btw couldn't 19790509 also be 5th Sep 1979 instead of 9th May?

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4 points by btilly 3 days ago | link

To the best of my knowledge, no. One of the reasons for the ISO date standard being YYYY-MM-DD is that there is no country in which the interpretation of a date given that way is at all ambiguous.

There are countries with DD-MM-YYYY or MM-DD-YYYY, so you really do have to put the year first to avoid ambiguity. However the 79 in 1979 cannot be a month or a day.

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-1 points by skibum 3 days ago | link

Oh it can't? Right. Like hey, let me salt a clue here. Oops, better make sure it's ISO compliant. I want to get hired later, after all...

Subtlety, obfuscation, and misdirection; welcome to the Middle East.

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1 point by aufreak3 2 days ago | link

I agree with what you meant to say, but I don't approve of how you said it.

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1 point by 16s 3 days ago | link

I've read that there are three stolen Microsoft Authenticode certificates being used by stuxnet authors to sign the malware. I've used these sort of certs myself to sign executables. They require passphrases to use. I could believe that they cracked one passphrase to use one cert, but three? All from different companies too.

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5 points by mfukar 3 days ago | link

It's much more likely that the certificate used were stolen (from Realtek Semiconductor Corp.), than cracked.

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3 points by illumin8 3 days ago | link

I find it more likely that the certificates were given to them by an employee that also shared the passcode.

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1 point by mfukar 1 day ago | link

Said employee also kept her mouth shut? I don't know, conspiracy theories are not my forte.

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2 points by 16s 3 days ago | link

Yes, but the point is that in order to use a stolen cert, you need the passcode and the cert. They somehow got three certs and three passcodes from three different companies.

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2 points by ww520 3 days ago | link

Sometimes companies embed the passcode in the build script to automate the build process. Having to type in the passcode every time to build a release can become a chore.

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1 point by mfukar 3 days ago | link

That's right. However, I think that if I were in a position to steal a certificate, it'd be trivial to also get the pass[code|phrase|whatever], assuming there even was one to begin with. ;-)

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1 point by ralphc 3 days ago | link

Realtek and JMricron were in the same building, maybe the third company is as well?

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1 point by atomical 3 days ago | link

I could see a lot of nefarious individuals learning from this and using it to cause tragedies for short-term gain (i.e. shorting a stock). It does seem quite stupid to open up the door on something that could cause so much harm.

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1 point by flipbrad 3 days ago | link

the possibility of it sinking BP's Deepwater Rig was interesting, not something I had considered before reading it in the Q&A

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1 point by statictype 2 days ago | link

Without Autorun enabled, how does code get executed on a usb drive?

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3 points by uxp 2 days ago | link

Even when autorun is disabled, Windows will parse through the autorun.inf file. This should have been patched with KB967715.

U3 enabled devices have been known to override the default settings in order to emulate CD-ROM drives.

Double clicking the flash-drive icon can also force execution of binaries, but I am unsure of how that works and if it is related to the user's autorun settings or not.

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2 points by Riesling 2 days ago | link

http://www.microsoft.com/technet/security/bulletin/ms10-046....

"The vulnerability could allow remote code execution if the icon of a specially crafted shortcut is displayed."

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1 point by twymer 3 days ago | link

"Siemens announced last year that Simatic can now also control alarm systems, access controls and doors. In theory, this could be used to gain access to top secret locations. Think Tom Cruise and Mission Impossible."

I've been reading pretty much everything I can find about Stuxnet so far, but haven't heard this before. If it's true Stuxnet might really be living up to the hype that it's the "first malware of it's kind."

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2 points by Garbage 3 days ago | link

One interesting question is: * Q: Was Stuxnet written by a government? A: That's what it would look like, yes.

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8 points by chris_l 3 days ago | link

Isn't the question better posed as was it funded by a government? And how did they choose whom to hire? Maybe the private armies are getting into cyberwarfare...

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1 point by user24 2 days ago | link

What's the difference between a govt writing it and funding it. Writing is a subset of funding.

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5 points by mh_ 3 days ago | link

While it is pretty difficult to answer what a piece of code written by a government would look like, a useful piece of information is also that the code targeted 4 different 0-day bugs [1]. If we consider previous reports on 0-day pricing [2], this alone could put the cost fo the worm at over $200000 making it more likely to be built by a well funded adversary.

[1] http://en.wikipedia.org/wiki/Zero-day_attack [2] http://weis2007.econinfosec.org/papers/29.pdf

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8 points by InclinedPlane 3 days ago | link

A talented individual or small team, government funded or not, is going to be able to research vulnerabilities on their own.

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3 points by charlief 3 days ago | link

Agreed, but I think the best evidence of large sponsorship is in that factory system recognition and parameter modification code. We don't really understand the sophistication until it actually chooses to execute, but access to those kind of specifications would require some fairly extensive research resources, someone that an individual or small team would have trouble getting alone.

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3 points by caf 2 days ago | link

It really doesn't matter if they bought the 0days or researched them themselves - either way they either spent the cash or gave up the opportunity to earn the cash from them, which is equivalent. They still put ~$200,000 worth of resources into the worm.

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2 points by rouli 3 days ago | link

yes, but a talented individual would probably sell those vulnerabilities since they worth so much, rather then use them for some obscure, probably not money earning, goal.

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1 point by InclinedPlane 3 days ago | link

That's just moving one layer of indirection. If vulnerabilities are worth money, presumably so they can be exploited, then why isn't it possible for someone to be motivated to use vulnerabilities and also having the talent to discover them?

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1 point by mfukar 3 days ago | link

You're making the assumption that a government would not pay for the development and exploitation of those vulnerabilities, which is de facto false considering the current "cyberdefense" capabilities of developed countries.

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4 points by nivertech 3 days ago | link

If it's indeed created by Israeli Intelligence, then at least R&D costs will be close to nothing. Israeli military has mandatory service. 18-21 years old programmers/hackers work day and night almost for free.

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3 points by rikthevik 3 days ago | link

I think there's some very experienced, very talented people working on this. Security is one area where I believe that the older you are and the more hours you've clocked and exploits you've thoroughly understood, the better you are.

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2 points by anonanonanon 3 days ago | link

Our defense budget is 7% of our GDP, which is the 5th highest rate in the world (according to wiki). I would hardly call that free. Also, there is a shortage of tech talent here and the salaries are quite high. So there are also hidden costs with the military getting people to work for "free".

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1 point by nivertech 3 days ago | link

First it's 8.5% of GDP in 2009, but in absolute numbers it's only $14.3B (including US aid, which has to be spent in US). This peanuts for being a regional superpower. About half of the budget goes to salaries of officers, permanent servicemen and civilian contractors.

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1 point by ErrantX 3 days ago | link

The danger there is the "common thinking" that this puts it squarely in the realm of governments.

However, at such a price point you're still well within the remit of organised gangs; they, for example, will spend a fortune on viruses and other malware - it's big big business.

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2 points by hugh3 3 days ago | link

Wait, since when have governments been better at writing code than small groups of talented amateurs? Have I fallen through a portal into mirror-universe HN?

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2 points by btilly 3 days ago | link

One of the arguments for it being a government is the unusual size and complexity of the code. A large piece of code speaks against a small group. It also speaks against a group with an ethos of producing something simple and elegant, which talented amateurs would be likely to feel.

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1 point by scrrr 3 days ago | link

This is the stuff of movies, but do you think its very wise to write this kind of software for a government? Perhaps if you can somehow stay anonymous..

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1 point by brown9-2 3 days ago | link

Eh? The implication/speculation is that a government wanted to create and spread a worm.

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1 point by scrrr 3 days ago | link

Yes but would you like to be the programmer that wrote it? You would also be a witness. Again, movie stuff.. :)

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1 point by uxp 2 days ago | link

You're assuming that a bunch of suits pulled some hackers out of their parent's basement and told them to write a virus.

I can only comment on the US Government's NSA, which has thousands of highly trained and highly intellectual programmers already under their employ. These are people that do their job to protect and assist in the affairs of the government. Probably already under highly classified labels. For some, it is just another job assignment.

However, I am also speculating. The truth: No one capable of telling the truth knows.

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1 point by somewhere 3 days ago | link

does anyone know where to get stuxnet from? can't find it on the regular virii sources...

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4 points by pilate 3 days ago | link

There's at least one sample on OffensiveComputing.

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-1 points by ErrantX 3 days ago | link

Take care. While this does have a lot of clear information about Stuxnet it also has lots of idle speculation and "wink wink" stuff.

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1 point by ErrantX 3 days ago | link

Ok, actually I do retract that. It's an excellent overview - I just didn't like the small pieces of speculation they did drop in without marking them as such ;)

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