start	end	text
19640	22000	It's been a long minute.
27010	29470	Okay, looks like we're good.
30490	39030	So, joining me today are Trey Cohen and Brenda So.
39110	44530	And I have the pleasure of congratulating you for your first time DEF CON talk.
44530	48430	And with that, we have a tradition where we share a shot with the speakers.
48430	53430	So, please lift your glass and welcome to DEF CON.
61240	62460	All right.
62460	63620	All right, yeah.
65260	71960	Then you spend the next few minutes trying to get your voice back after drinking Firewall, or Firewire, right?
73460	75260	I hope it's not Fireball.
75620	81040	Yeah, we could actually spend a half hour talking about Fireball if you want to, that's good.
81240	83320	But we actually do have a question coming in.
83320	92520	So, first question is, why on earth would a public ATM system use such easily defeated systems as Windows CE 6 and triple DES?
95700	96220	Well...
96760	98220	You can go ahead, Brenda.
98720	99620	Oh, okay, sure.
99620	100580	I'll do it.
102380	103680	I'll do it.
103680	109280	So, I think for retail ATMs, the main consideration for them is price.
109280	118120	So, like, the license for Windows CE is definitely cheaper than, like, more up-to-date, like, Windows 7 or Windows 10 ATMs.
118120	128700	In fact, a lot of financial ATMs, like ATMs you see at financial institutions like a bank, they would use more up-to-date Windows software.
128700	134280	As for triple DES, triple DES is more of an industry standard, I would say, for financial institutions.
134280	135320	That's how they use it.
136440	141380	Yeah. And, you know, we kind of touched on this in the talk, is, you know, we're...
141380	149740	There's a consideration to be had where, you know, you have this device that's been built, it's been out there for years, and, you know, hasn't caused you any issues so far.
150860	155200	And it's a reasonable price if you have all these systems built up around it.
156180	168400	You know, if it's not something that, you know, an end user is directly affected by, at least in the immediate term of being able to see, you know, oh, this ATM is insecure,
168840	175440	you know, you just assume your ATM is secure, you don't get any complaints about it, you can get it at a cheap price, just keep selling it.
175800	179300	That seems to be the motivation here.
180580	186620	Yeah, and if you are, like, a convenience store owner, like, looking to buy an ATM, the first thing you look at is price, right?
186620	192440	Like, you don't really... like, I do not think security would be in your mind when you're purchasing...
192440	197540	like, when you're just a store owner trying to purchase an ATM for customers to use.
197800	198360	So hence...
198360	199240	And everyone's...
199240	200260	Yeah.
200400	206920	Everyone's seen those videos of, like, the backhoe being, you know, pulled out to grab the ATM and dig it up and dump it in a truck.
206920	215220	I know physical security is a huge consideration, but network attacks are not necessarily the biggest consideration.
218340	219220	Great.
219220	223520	So, looks like you guys actually are winning on YouTube.
223520	227240	You've got 8,000 views on this, so it seems...
227240	238940	I think everyone was waiting for that Barnaby Jones moment, which, you know, I was a little bit disappointed to see you actually letting the cash drop into the, you know, the holder.
238940	245240	I imagine that was a pretty great moment to see that cash disperse, though, right?
245600	252820	Yeah. Barnaby Jack was a great showman there in terms of his talking, putting this out there initially.
252840	263220	So, you know, we're happy to be able to have something to try and, you know, follow up 10 years later and see, you know, are these still secure?
263360	266640	And can we make a really cool demo?
266640	275320	Probably not as cool, but, you know, at least try to attain the level of coolness of his talking and dumping some cash out.
278490	283290	Very cool. You mentioned that the ATM was capable of TLS and SSL.
283610	288310	Would the replay attacks have been possible if they had enabled that on the ATM?
288310	293230	Or was this protection on for the communication with the host processor?
293230	299330	So the replay attacks were for... the replays were for XFS.
299330	306950	So that's a completely, I guess, separate question there in terms of, you know, doing replays.
306950	319500	The replays were replaying traffic that was going on the loopback interface on the device and sending that over the network into the XFS middleware.
319500	331960	But the TLS and SSL is actually for communicating up to the RMS, or not the RMS, but the payment processor, I believe.
331960	333380	I'll let Brenda speak a little bit more about that.
333380	342140	Yeah, yeah. TLS and SSL are for communication with a middleman between the ATM and the credit card network.
342140	347790	It doesn't encrypt inter-process communication within the ATM itself.
351790	359650	Cool. So Hawkeye, who did not see the full video, I share that problem with Hawkeye.
360090	366430	Was there anything that you saw that you could do with the camera once you started compromising the machine?
367270	375210	So the ATM that we bought, the camera is actually an extra module that cost a couple extra hundred dollars. We didn't buy that part.
375210	379270	So we didn't really look at it, if that's what you're wondering.
379750	380870	Gotcha.
382590	394870	That is something that is a standard component on the middleware there, but in terms of how widespread that is, it's not something we're super familiar with.
394870	399610	But our ATM, certainly, the base model, lowest price, did not have that.
401150	406910	Yeah, at least it didn't come with a $3,000 pay per ATM.
408510	420910	Great. So another question is, can you explain more about which steps in the first 40 minutes of the video are necessary to exploit the cache disperse function over port 8004?
420910	429070	It seems like, for a while, you would need to upload new files and application binaries, which would direct the response to your payment processor.
429370	440450	But at the end, it appeared that all you needed to do was make the cache disperse, was to connect to the network, intercept the instructions, and resend them.
442010	453550	Yeah. A lot of what goes on here is, you know, there's kind of the old adage about, you know, you're not paying an automotive mechanic to hammer for, you know, an hour.
453550	455530	You're paying them to know, like, where to hammer.
455590	467430	So figuring out where to hammer for this ATM was a very long process, and that took a number of, you know, firmware upgrades on our end, adding our custom tools in there.
467430	470790	And, you know, progress kind of came in fits and spurts.
471050	482910	So, you know, Brenda discovered the RMS vulnerability, and, you know, we took that and kind of were able to build an exploit around that.
482910	491810	The XFS stuff was largely built on the ladder block and the debugging capabilities we developed there.
492030	503870	So being able to debug things, being able to figure out, you know, that these messages are going over the loopback interface, and being able to capture those was a whole process that took quite a while.
503870	509730	But then, at the end of the day, you're just sending a single TCP packet over the Ethernet interface.
511210	517270	As for the function that we find in IDA and the binary, that's more for an exploratory process.
517570	520910	So the cache dispense or the print receive function doesn't just do what it does, right?
520910	524330	There's a lot of setup involved, like, there's a lot of checks, etc.
524710	530990	So it doesn't really work well for, like, a direct injection, as elegant as the vulnerability that Trey has found.
530990	538170	But that helped us a lot in understanding how the ATM internals work, like, how, like, the processes communicate with each other, etc.
539730	552010	So, follow-up on that. Do you think that the understanding you were able to glean from doing that sort of reverse engineering on it, how much of that do you think transfers to the Windows 10 higher-end machines?
554750	556050	That's a good question.
557110	563590	So the vulnerability, so what matters, you're talking about the difference between the OSs, right?
563590	568570	So the OS, I would say that the OS and the application binary are separate.
568750	579890	So everything that we found, every vulnerability that we found is in the application side, and none of them relates on a kernel, like, depends on a kernel exploit.
580190	582050	So you can look at it like that.
582050	591790	And also, if you're talking about Windows 7 and Windows 10, we're talking about financial institutions that probably, like, poured in hundreds of thousands of dollars into securing their framework.
591790	596470	So I think it'll be interesting, but I'm not sure. We don't really have banks.
600290	605430	There's no asterisk to that, you know, so don't come after us.
606730	609190	I think, you know, that's a good point.
609190	624370	A lot of, at least in terms of the XFS vulnerability, that will depend on how much of their middleware is portable between the retail versions of the ATMs and the financial versions of the ATMs.
624370	629710	How much of that codebase is shared? Was there some refactor that happened along the way?
629710	645170	That's not something we have the resources to answer. We don't have these very large, expensive ATMs. We're focusing on these slightly more accessible ATMs that are, you know, a couple thousand, thousands of dollars.
645630	657350	Yeah, and even if we have the money, I don't think they would sell it to us. Can you imagine just calling a mom and saying, I want a financial ATM for 10 grand. They ask you, what is it for? And then you don't know what to answer, right?
657630	667710	But for the retail ATMs, you find, like, a distributor and just say, I want an ATM. And there you go. One showed up at the office.
669610	686970	And we also actually asked, we tried to purchase a license for the remote management software, but I think by that point they were kind of questioning why we would want to buy the remote management software and chose not to sell it to us.
687670	692790	But we were able to buy numerous ATMs just by going to this ATM distributor.
693550	701130	Wait, sure. Did you find a copy at the, what was it called, Wayback Machine? Like a copy of the RMS service?
701130	718830	So there is an older version of the software that you can find with a lot of work. This is not something I was able to find very easily, but there is something on the Wayback Machine where there is an error of this software.
718830	728310	I couldn't actually get it to work with our ATM, so I'm not sure how useful that would be.
732040	741340	Cool. So on the admin page, the ATM, did it have any ways to kind of harden the security, like requiring a larger pin or anything like that?
745440	758220	I think if the password is longer, maybe. But if you also think about the ATM inputs, it's just like a 10, there's only so many keys you can input, right? Like it's 1, 2, 3, 4, 5, 6, 7, 8, 9, and 0.
758580	770940	So it would be within the numeric range. But I think the security on that part is if you spend a lot of time just standing in front of the ATM and inputting every single key,
770940	781200	it will look suspicious at one point. But I don't know, but then the thing becomes whether someone actually comes up to you and asks you, why are you spending so long at the ATM?
784620	798560	Yeah, and again, there is that option for things like TLS and SSL, but securing it from an end user coming up and trying to just guess the password to administrate the ATM,
798560	806520	that's not something that seems to be much of an option beyond a six-digit numeric passcode.
810000	832680	Great, so one thing, you mentioned the initial research occurred over 10 years ago. Were you surprised that you were still able to fuzz that RMS after it was already exploited?
834020	836600	Can you ask the question again?
839720	858860	Yeah, I'm still learning English, so I'm not sure I can, but what I was trying to ask was, were you surprised you were able to fuzz and find something in RMS even after that was the specific path that was exploited over 10 years ago?
859580	872100	Yeah, we're pretty surprised. Actually, we did the reversing independently because at that time we couldn't find any information, so we just put our efforts, used all the tools that we had and reversed it for two weeks, right?
872100	886280	And then afterwards, we found Barnaby Jack's IOactive documents on the RMS protocol and how he exploited it, and when we looked at the two package structures that we found,
886280	896680	they're exactly the same, and the obfuscation or the encryption techniques are also exactly the same, so that was kind of surprising. I would have thought that something would have changed, but it didn't really.
898460	910740	Yeah, and that initial vulnerability was patched, although this was still something that was a bit of a separate issue that we discovered.
913160	922160	All right, so we have a question from the audience. Do you plan on continuing your research, and if so, would you play at the payment processor level if you had a way to get a hold of the right folks?
926420	937200	Payment processor... that would be interesting to look at, because when we were looking at the admin screen, the protocol that we reverse-engineered is not the only protocol that is there.
937200	948380	There are different kinds of standards for different kinds of payment protocols. I don't know why they need so many. There's four in total. I don't know why they need so many, but it's just there, so I think it would be interesting to look at those.
950060	964160	Yeah, that could be an interesting avenue. We started looking into a few other ATMs, but that's a whole other initial reverse-engineering effort that we want to undertake.
965400	976100	We actually stuck to this line of ATM, and the software between the smaller ATM and the larger one that we have is exactly the same, so that was very portable.
977780	989120	Yeah, and if you look at... I think on one side of the PowerPoint, we show that the two ATMs use the same firmware, but there are also other ATMs that also use the same firmware.
989200	999760	So the vulnerability that we find don't just affect the two ATMs specifically, but it affects every single ATM that uses that exact firmware update.
1003660	1016220	So one thing that came to mind when I watched the video was, I was wondering if your intern locking the key in was by design just to increase the challenge or just an accident.
1016760	1019340	Oh, that was an accident.
1019340	1035280	Yeah, that was not a fun afternoon to realize that you have an ATM, and the only thing that can open it is the second side of it, and the key, ordering it online while we're at it for another week or at least a few days.
1035280	1040120	So it's not great when you have a deadline for a CTF coming up there.
1043520	1057740	It's our initial effort. I think it's like a month in, and then we have a deadline. And then we just had so much reverse engineer efforts done at that stage, and I really need to do the firmware update, and some intern just locked it in there.
1057740	1069200	I think I got pretty pissed during that time. And that's why we spend so much effort. I can't wait. I have a deadline in two days. I can't wait for Amazon to come. I can't do firmware updates for two days.
1069200	1073080	We bought a lock picking kit.
1074440	1075700	Tubular locks.
1075940	1084600	Yeah, it doesn't come on time, and that's why we're printing the ATM keys. We just need to unlock it somehow.
1085260	1091020	Yeah, I was trying to chip away at some of the plastic on there and see if we could fish the key out from the inside.
1091960	1107380	Ang was like, yeah, you know, we've got 3D printers. We've got pretty nice 3D printers at the office. So he just went in and, you know, there's tubular lock keys you can download on Thingiverse or wherever we posted that from.
1107840	1120740	Just set what the pin should be, which on some keys is just written on the top of the key. So you can do an image search or a search online for this key and then the combination is just right there on the key.
1122020	1126700	Wait, Richard, didn't you open it with a claw tanger at one point?
1127480	1129780	There are other ways into the ATM.
1133460	1136020	I'll leave it at that. There are other ways into the ATM.
1137440	1140000	So intern still with you or not?
1140220	1141980	Oh yeah, he's full time.
1146020	1147860	Living inside the ATM.
1150020	1153560	I don't think you could fit someone in there. Maybe in the vault.
1154720	1157960	Yeah, maybe. Oh, yo, I think we could.
1159380	1161120	Do you want to volunteer for that?
1161120	1161840	No.
1161840	1167880	I think I'm the smallest person physically at a company. I still don't want to do that.
1170280	1173800	Pepper would fit. The office size.
1177780	1191820	So we actually have another legit question. It said, looking at the different parties involved, do you know who would be on the hook for lost cash if someone did such an attack from buying your ATMs? How are the contracts structured?
1193300	1195080	It's a great question.
1196100	1205820	The ATM industry, I think based off of what I've been looking at online as an end user, there's a couple of different ways you can go about buying an ATM.
1206140	1217100	You can be the one who physically owns the ATM and you do everything yourself, reloading cash, updating the software, connecting it to a payment processor, all of that.
1217640	1227600	Or you can go to a payment processor and sometimes they have partnerships where they'll make it easier to onboard and get things going.
1227600	1234620	Or you can just say, I have this spot. I want an ATM. I don't want to buy the ATM. I just want to cut off the top.
1234620	1239940	And whoever puts one ear, you know, you can take a cut off the top as well. So we'll kind of split that.
1240540	1254880	But, you know, there's different ways the ownership model for ATMs works. So it would depend on that. But as far as who's actually liable, that's not something I necessarily have the business insight to answer.
1256200	1263140	Yeah, we focused more on the technical part. We didn't really look at the legal and the economic implications.
1266560	1281520	Sure. So kind of looking ahead, what kind of things should the community take from your research and where can they take this kind of thing to the next step in taking a look at ATM security?
1282060	1292120	Which direction should we all be going after we get our ATMs delivered to our house?
1293800	1302340	So what we did is actually... if you look at the actual vulnerability itself, right, what we did is not that difficult. We didn't discover like...
1303320	1313660	Buffer overflow is not... we're not the first one to discover buffer overflow. We're not the first one to discover that, you know, you shouldn't broadcast your IPC communication.
1313660	1325560	Right. So even though reverse engineering took a very, very long time, the actual vulnerability discovery took around like two months or so. And we're pretty new at that as well.
1326020	1338620	So I think for next steps, maybe we can look at other attack vectors other than network-based attacks or to actually delve deeper into network-based attacks and see how one could attack that.
1339240	1349320	Yeah. And as an end user, as a consumer of ATMs, it's hard for you to have a voice in this power structure to say, you know, to demand security.
1349800	1358960	Normally, this is not something where you can go online and just navigate to a different website. This is like a real world physical thing where you're kind of stuck with what's in front of you.
1358960	1371620	So being able to tell a shop owner, hey, you know, this ATM is out of date, you know, you should update your software. That's a little difficult because, you know, it's not advertising necessarily what software version is running.
1371620	1383740	It's not saying, you know, I'm a Windows 66 device, which has been past the extended support end of life for a couple of years now.
1384460	1399100	It's a difficult problem. But, you know, raising awareness in the community about that and letting people be able to stop and think before you use an ATM, which you should do regardless, you know, with the proliferation of card scanners and everything out there.
1399100	1408680	But being discerning in terms of how you use ATMs is a difficult thing. And it's not an easy problem to solve.
1408680	1416600	But just having that voice in the back of your head saying this could be out of date, this could be having issues is a good first step.
1420660	1436200	So just a follow up to that. I mean, I think, you know, as you said, it's not like a small business owner can just go, you know, go switch to a different one overnight or even get the insight into something before they make the purchase.
1437300	1448080	You know, as a consumer, did you really... it seems like the stuff you found wasn't necessarily a risk to the consumer as much as it is to the owner of the ATM.
1448440	1454320	So, you know, you mentioned card skimming, but is there really anything you found that consumers need to be worried about?
1455500	1462840	So for the exploit that Brenda focused on, the RMS exploit, the one that she discovered, that allows for arbitrary code execution.
1463280	1471440	And the implications of that, you know, it depends on how far your imagination can take it and how creative the attacker can get.
1472540	1478040	So, you know, I'll hand it off to her. That's really more her spot to talk about.
1478960	1483980	It depends. We're talking about how a consumer can be affected, right?
1483980	1502880	Like, I believe in our demo, we demonstrated that you can, like, an attacker can extract information from, like, their magnetic strip or the credit card chip of their cards when they insert it and try to just, like, check for the balance or withdraw money.
1502880	1511460	So on the consumer's side, what's going to affect them is that their data would be compromised, right?
1511460	1527540	Because, like, the pin is encrypted, triple-desk. I mean, like, even though it's deprecated, it still takes a while to decrypt, sorry, crack the triple-desk, like, triple-desk pin number.
1527540	1533180	Just like your credit card information, every bit of information for a credit card chip can be extracted.
1539900	1540860	Yeah.
1542660	1544360	I think you're on mute.
1544880	1545960	Yeah, sorry.
1547120	1548860	Indeed, I am on mute.
1548860	1562580	So, and back to the physical security kind of aspect of this, based on the simplicity of those two locks that you encountered, do you think the ATM manufacturers should start installing more complex locks?
1562740	1571280	Or do you see a purpose for the locks that they choose? Like, why would they go with this if there are more secure options out there?
1571840	1582700	You know, sometimes you want to have a key that's keyed alike. You know, you want to be able to, you know, take a single key around and unlock numerous locks and be able to buy more of these locks that are all keyed in the same way.
1582700	1602080	But the issue here is that every single ATM of this model, the top compartment, we show the separation between the top of the ATM, which has all the electronics and the main circuit board with the computer, and the bottom part of the ATM, which has the cash dispenser and the cassettes with all the cash in them.
1602080	1614620	The top part, all the keys are the same. So, you know, really the first step there is making this not be a commonly available key that anyone can just buy.
1615820	1632000	So, you know, the bottom of the ATM certainly is quite a bit more secure. You have different keys, I believe, and you have the electronic lock on the ATM itself. So there's quite a bit of extra steps taken there to protect the cash.
1632000	1649440	But in terms of the main components there, that step would still be likely a good one to take to change out the cores and make different keys for different ATMs.
1653120	1658570	Cool. Did you guys work on any chip-based ATMs during your research?
1660710	1661990	EMB?
1669660	1672900	Like the EMB chip, I guess, right?
1673800	1684260	Oh, yeah. So our ATM supports both chip and magnetic strip. It's just an option that you set on the ATM side of things.
1684860	1696180	And if you're wondering whether your chip is encrypted, the answer is it's encrypted with TS or SSL if you enabled it. But if you don't enable it, it's just plain text.
1700620	1722880	Okay. Well, we have just a couple more minutes left. I want to thank you guys for your hard work and the effort you've all put into this. Fascinating stuff. I actually ran Barnaby's talk a while ago. It's kind of depressing that it's been 10 years. My goodness.
1724020	1735180	But it's good stuff. Congratulations to both of you. Is there anything else that you guys want to add for everybody that's come out to ask you some questions and everything like that?
1738490	1741930	I'm going to share my Twitter handle if you have something to ask.
1748390	1753070	If you have any questions, you can DM me. I'll be happy to answer any questions you have.
1756110	1759750	Same. I guess they're on the DEF CON website.
1761630	1771610	Yeah, ATMs are a fun target and it's been fun being able to work at this at Red Bull and over the past year and a half.
1772190	1773570	Year, year and a half.
1774770	1777430	These are interesting targets.
1779790	1795750	We're happy to be able to share this and demonstrate that these devices are out there. It's not something you can just go out on a whim and install in your own home, although there are special individuals who have taken those steps.
1795750	1800150	But these are fun devices to work with.
1801290	1811630	Like a lot of things, they benefit from not being as scrutinized by end users. It's more of a thing where you say, I want this.
1811630	1823130	As a Bodega owner, as a gas station owner, you just get this ATM and you don't have to ask too many more questions, as long as it doesn't just pop the vault open and spill out some cash.
1823130	1837910	Generally, that's enough for most people, but these devices are something that deserve being looked at through the network layer and seeing how they interact and which open ports they have.
1837910	1844310	It's just a simple question to ask that yields a lot of information about the security of the device.
1846190	1857110	So we have one last minute question, if you guys are game. Should the penalties for non-EM, EVM implementations be higher? They're currently very low.
1858490	1875450	It's a good question. I think a lot of payment processors actually require EMV nowadays. I know that there's some requirements by some companies or financial institutions. I'm not quite sure how that works.
1877030	1884190	I think it's fairly widespread, at least in terms of what I've seen. Brenda, does that mirror your experience?
1884930	1903650	Yeah, most ATMs I've seen uses EMV, at least the ones I've seen, right? But the fallback, if your EMV doesn't work, the fallback would be a magnitude shift, which goes back to the same original problem.
1903990	1915430	Great. Well, I appreciate you guys being generous with your time, and I appreciate you guys joining us today. And thank you for all the questions from the field, and we hope to see you guys back with more research in the future.
1916510	1917790	Glad to be here.