Our main goal at Sucuri is to make the internet a safer place. One of our investments is creating the best educational content about website security to share our knowledge with the community. With that in mind, we have decided to start podcasting.
The Sucuri Sit-Down podcast aims at explaining what is going on in the website security field. We are going to talk about the latest website vulnerabilities, attacks and hacks. We are also going to interview website security experts.
We have also launched the Sucuri Sync-Up, our weekly website security news briefing.
You can find this wherever you get your podcasts, as well as our social media, and a flash briefing on Amazon Alexa smart speakers. Just search Amazon skills for “Sucuri Sync-Up,” to add the flash briefing and get new content delivered every week. It should be coming soon on Google Assistant briefings too!
Talk to us in our social media channels if you have any content suggestions for our podcasts. Stay tuned!
Justin Channell: Hello, and welcome to the first episode of the Sucuri Sit Down. I’m your host Justin Channell and this podcast is here to bring you a recap of what’s been happening in website security for May 2020. Later in the show I’ll have our analyst Ben Martin on to discuss a credit card skimmer that was found on a WordPress site running WooCommerce, but first we’re going to take a quick look at other topics that we’ve published on our blog and Sucuri labs this month. First up, we had an analysis of malicious code that revealed reconnaissance strategies for hackers that were targeting WooCommerce. Our analyst, Luke Leal, said that the reconnaissance is performed by a malicious file that was injected into a website’s hosting environment, and this allowed a bad actor to map out WooCommerce installs from the same C panel user. Another topic that Luke wrote about on the blog was that our remediation team found a fishing campaign that was targeting YouTube creators.
The attack was first discovered on a compromised WordPress site, and it was designed to appear as though the victim received a YouTube creator award. Now in this attack, bad actors were looking to gain access to the victim’s username, password and recovery phone numbers with the recovery phone number, of course, being there to bypass any two factor authentication on the account. Once the victim would give up that information, it would be sent out through a PHP file through two separate post requests, and at the time of discovery, the malicious domain found in the redirect had not been blacklisted by any other major vendor. Now, during a routine research audit for our firewall, we discovered an unauthenticated persistent cross site scripting vulnerability in a WordPress plugin. This affected more than 40,000 users of the WP Product Review plugin. Our researcher, John Castro, said the bug has been fixed in the latest version.
So users of WP Product Review are urged to upgrade as soon as possible, also worth noting is that there were some interesting malware campaigns and vulnerabilities that came about from COVID-19 in April. This includes what we would expect, which are SEO spam and phishing campaigns using language that really played off of the fear and uncertainty of the pandemic. But one interesting vulnerability that came about was in WordPress learning management software, Lindsey O’Donnell at Threatpost had a story about a flaw that allowed students to steal personal information and gain teacher privileges to change grades. So, hopefully any educational resources have updated their LMS plugins. Now the three that were targeted were LearnPress, LearnDash and LifterLMS. So those three are going to be especially important to keep up to date. Now, April also saw eCommerce platforms take a big hit from hackers. Our teams reported new skimmers found on eCommerce sites running on open source platforms like Magento and WooCommerce, but even paid platforms like PinnacleCart.
Now, that WooCommerce skimmer blog post got a lot of people talking. So I wanted to get the chance to let Ben Martin, the analyst who blogged about the skimmer, to sit down and explain it a little bit more. We’re going to be sitting down with Ben in just a moment, but first I wanted to let you know about the Sucuri Sync-Up. That’s our weekly website security news briefing. You can find this anywhere you get your podcasts as well as our social media and now on Amazon Alexa smart speakers. Just search ‘Amazon skills for Sucuri’ that’s S U C U R I Sync-Up and add the flash briefing to get new content delivered every week now on with the show.
All right, so I’m here with Ben Martin. He’s a security analyst here at Sucuri. Ben, can you tell us a little bit about what you do?
Ben Martin: Yeah, I would love to, happy to be here. Thanks for having me on, my name is Ben I hail from Victoria British Columbia, and I’ve been a security analyst at Sucuri for just about six and a half years now. I’ve been, working in the trenches, cleaning websites for quite a while now. I mean, basically the short of it is when your website gets hacked, what do you do? You call Sucuri and I’m the guy that cleans your website, removes the malware. I work with a lot of websites, kind of the more difficult cases, I work with a lot of eCommerce websites, I work not just with WordPress, but I work with Magento and PrestaShop and OpenCarts and now recently we’ve started to see credit card swipers on WooCommerce. I wrote an article about it that was posted on our blog.
Justin Channell: That did really well, it got picked up a little by a lot of publications, like Bleeping Computer and Threatpost, and it was the most popular story on our blog last month. A lot of people were, talking about it. So that’s why I kind of wanted to have you on to dig into it a little bit deeper. Can you tell us exactly how does it work?
Ben Martin: Well, that’s an excellent question. I think the first time we saw a credit card swiper targeting WooCommerce was kind of late last year, but the same malware was also affecting Magento websites. So it wasn’t necessarily targeting the WooCommerce platform, but this was the first time that I’d actually seen, a dedicated purpose-built credit card swiper targeting the WooCommerce platform. This wasn’t like a vulnerability and WooCommerce, there’s nothing wrong with WooCommerce. A lot of people think, they probably saw my blog post and were like, ‘oh no, WooCommerce isn’t safe to use anymore’ but no, it just so happened to be targeting it. There’s nothing wrong with WooCommerce, it’s a fine plugin, as long as you keep your stuff updated, it’s safe to use it’s okay.
In fact, it is the most popular eCommerce solution on the web now. So far as that’s concerned, it was only a matter of time before we started seeing attacks targeting this platform. But what was interesting about the malware is that it didn’t actually target the WooCommerce files themselves. If you are a WordPress eCommerce website owner, and you use WooCommerce, and you start getting complaints from your clients about ‘my clients or credit card details are getting stolen.’ Well, the first thing you’re going to do is probably re-install WooCommerce or, check those plugin files, that stands to reason, right? But this attack wasn’t targeting those files at all.
Similar to another client that I worked with last week, another new WooCommerce credit card swiper, both of these attacks targeted files that were sure to load on all pages of the website. In the first instance, the case that I wrote about on our blog, it largely targeted the WordPress core files, right? So of course, that’s going to load on pretty much every page on the website, depending on which files you target. And this other client that I worked with last week, the targeted files were interestingly Google Analytics, because that is going to load on every page on the website, right? So it was a clever kind of maneuver by them. In the first instance it was, I mean, honestly, it was pretty easy to find because a check of the integrity of the WordPress core files is kind of the first thing you do, if you’re not able to find the payload on a website. But the second case that I worked with last week with the Google Analytics injection, that was a little more sneaky because you’re talking about checking the plugin integrity of the files, right? And there are thousands of WordPress plugins and there’s sometimes dozens, hundreds of different versions of those plugin files. But to answer your question, basically the short of it is that the attackers would intercept the payment details or the transaction details, credit card numbers, verification codes, all that stuff, and dump those details into an image file that was somewhere in WP content/upload/whatever, and download them and then clear the files. That was an interesting thing because when I saw in the malware that it was dumping the payment details into these image files, first thing you’re going to do is, well, let’s check out those image files and see what’s in there. And they were all empty. Which was very interesting because normally attackers are not so … usually they’re lazier than that.
So I think what they were doing was actually grabbing the payment details from these image files and then saving them and then clearing out the files. What does that do? Well, that makes it more difficult for the website owner to understand the scope of the compromise. How many of my clients were infected? Who do I notify to contact their credit card companies? That information’s just not there. I mean, it was very interesting. Like I said, it was only a matter of time before we started seeing this. And in fact, if anything, I’m surprised that it took the attackers so long to start targeting WooCommerce.
Justin Channell: Yeah. And now we know a little bit about what the attackers were doing when they got in there. How did they get in, in the first place?
Ben Martin: I get asked that question every single day at work. We don’t do a lot of forensics at Sucuri. Our position is typically just burn it all. Change all your passwords, because I find that trying to pinpoint exactly how they got in and which vulnerability did they exploit and which command did they run and what country were they from, in my view encourages a very myopic, narrow scope of what you’re concerned about. If your website gets infected, just change everything. Change all your passwords. But in any event, I’m not entirely sure exactly what caused the compromise, but attackers typically go for low hanging fruit. So really all they would have to do is brute force a WP admin administrator account and then they’re in. That’s it.
Brute force, for those of you who aren’t aware is trying sequentially all the most common passwords until you get in, which is why obviously it’s very important to have long and complex passwords. But I mean, really all you have to do … I see this every day, all the time, once the attackers can establish … once they’re into WP admin and get their administrator access, injecting the site is trivial. It’s child’s play. All you have to do is go to the theme editor, go to the 404.php file, upload your filesman backdoor web shell, and then connect to that, and then you have full access to the file system. You could connect to the database, everything.
So probably if I were to guess, the attackers got in through probably WP admin and once you’re in there, you can … by default … and this is one of those many examples of why out of the box configurations are typically not very secure is because WordPress wants to be easy to use and it wants to be convenient. And so by default, unless you turn this off, administrators can directly edit files on the file system. And so all you have to do is go to the theme editor, upload your backdoor, whatever, there, you’re done. Easy, trivial. Which is one of the reasons why in the blog article that I wrote is that you should … unless you make heavy use of the direct file editing from WP admin, turn that off. So all you have to do is disallow file edit to your WP config file and even if one of your admin accounts gets compromised, they’re not going to be able to edit files in that same way.
Justin Channell: Since it was only a matter of time really until a WordPress eCommerce site running WooCommerce would get targeted by a credit card swiper, what kind of a eCommerce site … or what kind of malware usually targets a WordPress site? What do they usually see whenever you’re cleaning them up?
Ben Martin: Oh, just regular … Regular for me, as a security analyst. Phishing, spam, Viagra spam, redirects to tech support scams, redirects to adult dating websites. This is the usual stuff that we see and I’ve even seen Magento websites compromised with this, from my perspective, pedestrian, run-of-the-mill everyday malware. So that’s usually what we see on WordPress. Again, the attackers always go for low hanging fruit and the more difficult it is for them to attack or spread their malware, the less you tend to see it. And so this is also why in the wake of new vulnerabilities that get disclosed and popular plugins or themes, you’ll see spikes in certain types of malware that will affect thousands or tens of thousands or sometimes more websites. But usually it’s spam, phishing, malicious redirects is the stuff that we see the most. But I work with a lot of the more difficult cases that come to Sucuri, and so I work with a lot of eCommerce websites. So I see a lot of credit card swipers too.
Justin Channell: Now, in terms of swiper versus skimmer … Sometimes I hear those terms a lot. Now, are those the same thing? Are they interchangeable or is there a difference between one or the other?
Ben Martin: They are interchangeable terms. They’re basically the same thing. And one interesting quirk about this type of malware that I did mention in the blog article at Sucuri, the amount of money that these attackers make on stolen credit cards are … you have to steal a lot of credit card numbers and sell a lot of them on the black market for them to be profitable. So in fact, for anybody interested in internet security, I would recommend the book Spam Nation by Brian Krebs. He goes into a lot of stuff, but one of the interesting things I learned from that book was that credit cards can go for as low as a few … a stolen credit card number on the black market can cost a couple dollars, like
Two or three bucks because the rate on returns is low. So if you buy a credit card number off of the dark web, if you want to call it that, you have a very limited amount of time to use that credit card and a limited number of things that you can buy with it. Because the first thing that’s going to happen is that as soon as the credit card owner looks at their statement and sees these strange transactions they don’t recognize, and activity out of Estonia or whatever, they’re going to call their credit card company and they’re going to cancel it. And so they can’t actually do much with a lot of these cards. And so you actually have to have a pretty substantial amount of these cards to make any meaningful sum of money with them. And some people do, but you know, probably most attackers aren’t even making that much cash on them anyway.
Justin Channell: Yeah. And probably even with… Most banks are going to alert people probably before even they see it on the statement. Generally, I think anytime I’ve ever had a card number compromise, it’s like I get the call pretty much within seconds of them trying to use it. So I don’t know if that’s the same with all banks or if I’ve just been lucky every time, but yeah. I’ve always questioned like, well, how long do they even get to have those numbers and really get to have that pay off at the end. Now, one thing I was kind of curious about is how does it work with dumping the information into a JPEG or a PNG image? Is that akin to real images? Or does it just kind of like dump it into a file that’s been named JPEG to hide it?
Both are true. I’ve seen both. In fact, there was another blog piece I wrote God, I think it was a couple of years ago now, but it was a Magento website. I mean, you can, if you’re writing a piece of code, you can make the output dump to whatever you want, right? It can be dot PNG or dot JPEG or whatever. Most of the time, they just happen to have that file extension. And if you actually try to open it in your browser or whatever, it’s just going to say error loading the image. But I’ve seen cases before where it was a fully functional image and related to the products that the website was selling, which was very clever.
In this case, I don’t know because the files were zero bytes in size by the time it got to them. I would say it’s probably a lot more common for them to just happen to have that file extension and not actually be custom images. Because I mean, by the time their malware is found by someone like myself, for example, I’m going to see whatever content has been dumped in there, whether it’s a legit image or not. So it’s not in a super effective way of obfuscating or hiding their tracks, but I have seen both before.
Justin Channell: How have skimmers evolved and increased over the years?
Ben Martin: Oh, very good question. I remember it was the autumn or winter, I think, of 2015. And we started seeing all these Magento websites come into our queue. Most of the websites that we work with naturally are WordPress and that’s not because WordPress has any inherent flaws in it or anything like that, it’s just that it is the most commonly used content management system, therefore it is the most targeted. And, and so there’s nothing wrong with- I hear a lot of people say things like, oh, people get hacked because they use WordPress or Magento. Like, no. That’s not how it works like at all.
But I think it was the winter of 2015 when we kept seeing these Magento websites come into our queue, which was very odd for us. We had never seen so many e-commerce websites come at kind of the same time. And that was when credit card swiping kind of really took off as far as I know. I’m sure it was a thing before that, but that’s when it started becoming kind of more commonplace, more organized and, certain platforms were getting targeted with malware, in this case, Magento. Now that kind of didn’t really change much for a while. You would sort of see the same types of malware pop up on other eCommerce platforms like PrestaShop and OpenCart and X-Cart and osCommerce. In many cases, interestingly, a lot of this malware is kind of, kind of interchangeable.
When our research team writes a signature for credit card swiping malware, they’ll often name it Magento shoplifts zero one three, or whatever, right? And then you’d be working on a PrestaShop website and you’d see a Magento signature get triggered. So it’s like, they’re targeting multiple platforms with exactly the same malware. And why wouldn’t they, right? So that didn’t really change up until just a few months ago where, and I’ve been seeing WooCommerce swipers pop up a lot this year. 2020s is definitely the year when that has shifted over to the WordPress e-commerce market and why wouldn’t it, right? Again, I want to stress that it’s not like they’re targeting it because it’s vulnerable or there’s something wrong with it, it just so happens that that’s a very popular e-commerce solution for small business owners, and so it was only a matter of time. And I’ve been seeing new WooCommerce swipers, like all year. They’re popping up a lot.
Justin Channell: Wow. So what do you recommend to WooCommerce store owners and even just eCommerce store owners in general that want to avoid hacks and any kind of credit card swipers getting on their site?
Ben Martin: Well, number one is take security seriously. I can’t stress that enough. It is something that’s, I mean- I’ve been working with website owners for many years now, and the trend tends to be that people don’t seem to care about security on their website until their website is belching out malware and blacklisted by Google. It’s kind of a very reactive attitude that people have towards it.
So the number one thing, just generally speaking that I would recommend, is that if you are, I mean, any website owner at all, but especially if you’re dealing with people’s payment information, processing transactions and whatnot, is that you have a responsibility as a website owner to take care of those people. Because a lot of stuff can go wrong, as I have seen. So number one would be take security seriously. What does that mean? Keep all of your software up to date, don’t have unnecessary plugins or themes installed, have long and complex passwords, use file integrity monitoring, we have the security scanner, WordPress plugin that you can use. Just all the basic stuff that we’ve been talking about for years.
I would say also, as I mentioned at the beginning of this interview. If you do not heavily rely on direct file editing in WordPress, you should disable that in WP config. Obviously having a SSL certificate is not going to hurt, it’s not going to prevent you from getting hacked, but have one anyway.
I think that you should also … as a eCommerce website owner in particular, you’re probably going to want to choose your platform pretty carefully. So for example, if your website store doesn’t really require you to have a high degree of customization or a lot of custom stuff you want to do with it. Then you could use something like Etsy or Shopify. You can just offload all that responsibility onto someone whose job it is to keep that secure. And then you don’t have to worry about it. So choosing your platform.
And if you’re going to use a WordPress and WooCommerce, or if you’re going to use Magento, or if you’re going to use PrestaShop or whatever. Just make sure you choose your eCommerce solution based on the needs of your store. And if you don’t require a high degree of customization or crazy plugins you want to use or whatever. Then choose something else. That being said, WooCommerce is fine. Magento, if you keep it up to date and patched is fine. All of these eCommerce solutions are fine. But they have varying degrees of responsibility associated with them.
So for example, Magento is a little … to say the least, a little more tricky to maintain than a WordPress, WooCommerce store. It’s not necessarily just a one click update that you can just do when you have your morning coffee or whatever. And so typically, Magento websites, a lot of them are dealing with not tens of thousands, not hundreds of thousands. But kind of millions in dollars of sale. And so they have that ability to kind of scale and invest in maintenance and all that sort of work that’s just associated with having a website. But if you’re selling widgets and trinkets, then you don’t need something so complicated.
And another thing that I touched on briefly earlier is that, there’s a common myth that, Oh, well, people get hacked because they use WordPress. Or people get hacked because they use Magento. They get hacked because they use these prebuilt solutions. And I have worked with clients who have custom coded their own eCommerce websites. And I’ll tell you, it’s not pretty. Those things are more vulnerable than anything else I’ve ever seen. Because e-commerce is very complicated. It requires all sorts of degrees of different features and requirements.
And those things are best, I would say, best left to the open source community. Because when there’s security vulnerabilities and patches that need to be issued. Yeah, that happens. It does happen. It happens with any software. There will be bugs, there will be security vulnerabilities, there be patches that need to be issued. But when you’re working with software, like WooCommerce, like Magento, like WordPress, you have the open source community there to spot those bugs and to write patches for them. And react to whatever problems happen with them.
So I would say that, the fact that people get hacked because of the certain software that they use is a total myth. The fact of the matter is, if you don’t want any bugs or security vulnerabilities in your software, then don’t have software. But that’s obviously not how the web works. And so that’s just the reality and what we have to deal with. And that’s just kind of how it works.
Justin Channell: Yeah. Yeah. Now in your time here at Sucuri, what is the coolest malware that you’ve encountered?
Ben Martin: What a wonderful question. I have seen everything under the sun. I’ve seen all sorts of crazy malware. I’ve seen malware that … incredibly complicated stuff. And I’ve seen malware that will delete the database just purely out of spite or I’ve seen a lot of things.
But I would say that probably the coolest hack that I’ve ever seen was something that my colleague Caesar wrote about. And it was an open cart hack. And all it was, was one character. It was just the comment out character. And what it did was it commented out the part of the CMS platform that authenticates the password. What happened was they just put in one character. And so when you’d go to website.com/admin, whatever it was, you would just press login and then you’re in the admin section.
Justin Channell: Wow.
Ben Martin: Without having to enter in a username or password. And that was incredible, like credit where credit was due. That was awesome. Like that was awesome. So hard to find like one character difference. And then they had like full administrative access to the website just from doing that one tiny little thing. So that was easily the coolest hack I’ve ever seen.
Justin Channell: Wow. That does sound amazing. Amazing what the power of just one single character can do.
Ben Martin: One character. Yeah, that’s all it took.
Justin Channell: All right. Well, Ben, thank you very much for coming on and explaining a little bit more about that to us.
Ben Martin: Hey, my pleasure and hope to be on again sometime soon.
Justin Channell: Thanks again to Ben Martin for being our first guests on The Sucuri Sit Down. We’ll be back with another episode next month. So be sure to subscribe on Apple podcasts, Spotify, Stitcher, or any podcast platform. Also be sure to follow us on social media at Sucuri Security and check us out at sucuri.net. That’s S-U-C-U-R-I .net for more security content. I’m Justin Channell and this has been the Sucuri Sit Down. Stay safe out there.