Welcome back, aspiring cyberwarriors!

Part of our work involves supporting red team engagements. We review completed tests, size up the risk tied to each vulnerability and build out recommendations for shoring up the infrastructure. This time around, we wanted to pull back the curtain on something special. It’s ATM security. 

This article is written to help with security assessments on ATMs, showing possible vulnerabilities you may find. It covers many things, from running malware bought off a forum, to an insider on the bank’s payroll, to a service technician who understands the machine’s internals and has been handed broad access to the equipment. We also look at whether a hacker could get into the bank’s broader network simply because the perimeter wasn’t locked down well enough.

Nothing here is meant as a tutorial. We’re documenting weaknesses hackers could exploit so that defenders know what to fix, not handing anyone a blueprint. We take no responsibility for how this information is used.

With that out of the way, let’s start with where ATMs came from.

The History of ATMs

London got the world’s first working ATM on June 27, 1967. It was primitive by today’s standards, incapable of checking a balance, which is exactly why withdrawals topped out at 10 pounds, and it dispensed cash only against special vouchers rather than reading a card. 

Nearly six decades later, ATMs look nothing like those early cash dispensers. Now they are multifunctional devices, but the hackers never stopped circling. Part of the appeal is obvious. An ATM sits on a pile of cash and offers quick access to it, and there are simply too many machines scattered across too many places to guard them all closely. A lot of them sit in isolated, low traffic spots that run unattended around the clock, think gas stations. That has shaped decades of security investment, most of it aimed at physical hardening. Today’s units can weigh over half a ton and come loaded with sensors tracking position, internal temperature, and whether a compartment has been pried open.

Here’s the catch, though. The safe holding the cash is genuinely hard to crack, but the compartment housing the control electronics is a different story, and in our assessment, it remains poorly defended. That gap opens the door to logical attacks, ones that skip the crowbar entirely and go after the software instead, and that category has been gaining ground fast.

Cisco Talos has tracked a steady climb in new ATM malware variants since 2009. The raw sample count still looks small next to other malware families, but don’t let that fool you. Europe alone saw logical attacks on ATMs jump 269% in 2020 versus the year prior, and the average payout per incident ballooned nearly a thousandfold across that same window, climbing from roughly a thousand euros to well over a million.

What changed the game was availability. ATM malware used to be a rare, closely guarded tool. Once it started circulating more freely on underground markets, prices fell and so did the skill required to use it. Cutlet Maker, which surfaced in 2017, is a good illustration. It came bundled with a Russian language manual complete with troubleshooting notes for running it against different ATM models.

Fast forward to 2024, and vendors on those same markets were offering ATM malware through subscription pricing, monthly plans included.

Logical attacks have always had one real weakness. They take skill and patience to pull off. That’s why cheap, well documented malware kits have had such an outsized impact on the trend. Their upside for hackers is just as real. They’re far quieter than smashing a machine open, and they often let the same person come back to a compromised ATM again and again. Manufacturers have started fighting back on the hardware side too, with tamper protected cassettes that flood the cash inside with indelible ink the moment someone tries to force them open, ruining the bills instantly.

Brief Attack Statistics

The numbers tell their own story. ATM related crime climbed 600% between 2019 and 2022, with 165% of that increase packed into 2021 and 2022 alone. Physical break ins, which have always driven the bulk of ATM crime, contributed alongside the rise in logical attacks. Germany had 496 ATM explosions recorded in 2022, a record for the country. Zoom out globally, and incidents of that kind blew past 18,000 in 2023.

Losses have kept pace. Banks worldwide absorbed $2.4 billion in direct losses from ATM fraud by the close of 2023. Europe’s share came to 173 million euros, with 67 million of that tied specifically to skimming. The United States handles just 25.29% of global transaction volume yet accounts for 42.32% of global losses. Skimming remains a big part of why, showing up in 45% of all ATM fraud cases in 2023 and costing North America over $900 million, with more than 315,000 cards compromised across at least 3,000 financial institutions.

None of this is happening in a vacuum. The market for ATM protection has grown right alongside the threat. Still, priorities inside most banks remain lopsided. Physical security tends to get the lion’s share of attention, while the operating system, drivers, and control software logic running underneath often get treated as an afterthought. That imbalance carries real consequences. A 2022 RTM Group study found that hackers could breach an ATM’s housing without setting off an alarm in one out of every two attempts, giving them free rein to tamper with the equipment inside.

How an ATM Is Built

Making sense of how these attacks work starts with understanding what happens inside the machine during an ordinary transaction. We’ll walk through that process using one representative configuration, illustrated in the diagram below.

The diagram reflects one specific setup we’re using for illustration, not a universal default, since real world configurations vary by device.

1. User Layer

From where the customer stands, using an ATM is simple. They need to present a card and pick a transaction. That wasn’t always the whole story. Inserting a physical card into a reader used to be the only entry point, and that reliance on the magnetic stripe made skimming and shimming, techniques aimed at stealing card data to produce counterfeit copies, a persistent problem for years.

Contactless cards changed the entry point itself. NFC readers now sit alongside traditional card slots on most machines. 

A PIN code layers on additional protection against someone using a stolen card. Entry happens through an encrypting PIN pad, a combination of physical keypad and cryptographic module that ensures the PIN never travels or gets stored anywhere in plain text. Verification of the resulting encrypted PIN block happens back at the processing center. 

Once identity checks clear, you can withdraw cash, check your balance, transfer funds, and so forth. There’s a full computer running inside the housing, but customers never get anywhere near it directly. Every interaction they have flows through a single banking application running in kiosk mode, locked to full screen.

2. OS Layer

That computer we just mentioned lives inside what’s called the service zone, and this section covers what happens there, setting the cash handling hardware aside for the moment. Physically, the service zone is protected by a thin door and a basic lock. Machines from the same product line frequently share an identical key too, one that’s often available for purchase online with minimal effort.

Beyond the system unit itself, the service zone also houses the ATM’s networking equipment and its wired connections to the card reader, contactless reader, PIN pad, and dispenser, typically running over USB, Ethernet, PCI, or COM interfaces depending on the device.

Windows powers most of these systems, historically through Windows Embedded and increasingly through Windows IoT, a Windows 10 variant built for embedded use.

The kiosk application isn’t the only thing running on that OS. Alongside it sits the ATM’s control software plus a handful of security tools. That can be antivirus protection, Windows AppLocker that keeps unauthorized programs from executing, and a VPN client that maintains a secure tunnel back to the bank’s internal network.

Control software is arguably the most important piece at this layer. Core responsibilities for the control software boil down to managing peripherals and communicating with the processing center, though specific implementations often add more on top of that. Some bundle in software for a monitoring server, letting technicians manage an entire network of self service machines remotely. Others are built in a supervisor mode meant purely for technical staff, offering quick access to diagnostic tools through a hidden menu to simplify physical maintenance visits.

3. Network Layer

Selecting a transaction sets off a verification process handled entirely by the processing center, a server living on the bank’s internal network. That server confirms the card data is legitimate, checks the PIN again before letting the transaction through, rules out any restrictions on the account, and verifies there’s enough balance to cover the request.

Everything exchanged between the ATM and the processing center travels encrypted, usually through a VPN tunnel, protecting against interception or tampering along the way. NDC and DDC are the most common messaging protocols in this exchange, functioning as something of an informal industry standard even before multi-vendor control software became widespread. ISO 8583 and its various offshoots see heavy use as well. 

The processing center isn’t the only thing an ATM talks to. Many machines also maintain a connection to a monitoring server used for remote management, health checks, and pushing updates, and unlike the processing center link, this channel frequently runs without any encryption at all.

4. Firmware Layer

Once the processing center signs off, the control software hands things over to the dispenser for a withdrawal, or the deposit module if cash is going in. These components typically sit inside the most fortified section of the ATM, the safe zone, built from tougher materials and secured with its own dedicated key separate from the service zone. 

The dispenser counts out the required banknotes from the ATM’s cassettes, moves them into position at the dispensing tray, then opens the shutter, the physical flap that blocks access to the cash until it’s ready. Data moving between the control software and the dispenser can be encrypted, and both sides authenticate one another before any exchange begins, a safeguard against device spoofing. All of that encryption and authentication logic lives directly in the dispenser’s own firmware. 

Deposits work differently. Incoming banknotes pass through a validator that checks their authenticity.

ATM Attacks

With the mechanics of an ATM covered, we can turn to the threats themselves. Every attack against these machines falls into one of two broad camps, physical or logical, depending on what the hacker is going after and how they approach it.

Physical attacks go straight after the machine or its components, aiming to extract cash or knock the device out of normal operation without touching a line of code. These predate targeted malware by decades and don’t require much specialized skill. Some don’t even target the machine itself, focusing instead on the people standing in front of it.

Logical attacks operate on a different level entirely. They demand genuine technical skill and preparation, built around exploiting weaknesses in the ATM’s software and network layers. They draw less public attention than physical attacks despite posing a bigger threat to banks, largely because they’re quieter and let a hacker return to the same compromised machine to cash in more than once.

System attacks go after functionality or logic running at the ATM’s OS layer, typically aiming to extract cash or sidestep security controls outright. Black box attacks deserve special attention, where a hacker skips gaining OS access altogether and instead wires their own device directly into the dispenser to control it externally. The same technique can target other peripherals, like the banknote validator.

Network attacks aim at the ATM’s networking components instead, with hackers looking to intercept, forge, or otherwise abuse data in transit, or to seize remote control of the machine. With weak enough safeguards in place, a hacker can forge the responses coming back to the ATM and push through a cash withdrawal even after the processing center rejected it.

Not every attack in this framework ends with cash in hand. A hacker might, say, work to gain remote network access first, then pivot into an OS layer attack from there. 

We have seen cases where compromising a single ATM meant compromising the entire bank because there was no network segmentation in place. Conversely, gaining access to the bank’s internal network could provide a path to ATMs and other critical systems connected to it. Credential reuse and a lack of understanding of Active Directory security can lead to devastating consequences in environments like these.

Summary

ATMs have evolved from simple cash dispensers into complex and networked systems. Their security has evolved unevenly alongside them. Physical hardening has made the cash safe itself genuinely difficult to crack, but the service zone housing the control electronics remains comparatively exposed, and that gap has fueled a steady rise in logical attacks. These attacks demand more skill than a physical break-in, but they’re increasingly accessible because of well-documented malware kits.

Cybersecurity is a vast field, and we offer courses covering a wide range of topics, including Active Directory Hacking, Wi-Fi Hacking, Web Application Hacking, SCADA Security, and much more. Our course library is constantly growing as we continue to add new training, all of which is available through our Member Gold plan. If you want unlimited access to our entire training library, including our most advanced courses, consider upgrading to Subscriber Pro.

The post Pentesting: A Look at ATM Security first appeared on Hackers Arise.

Welcome back, aspiring investigators! 

Let’s talk about something that has become one of the biggest problems in the crypto world. It’s drainers. If you haven’t heard the word before, don’t worry, you’re about to become very familiar with it. Drainers are a type of phishing attack, and they have swept through the cryptocurrency world at a truly striking pace. In fact, they are now growing so fast that they have already overtaken ransomware, both in how widespread they are and in the sheer amount of money they steal. To understand exactly how this works, we dug into the mechanics of drainers as well as the whole shadowy little market that has grown up around them. That’s what we are going to explore together today.

The basic idea behind any phishing campaign is to catch you making a mistake. Hackers want you to hand over information or access that should never leave your hands. In the specific case of drainers, the goal is a little different from classic phishing. The hacker wants to trick you into granting a smart contract permission to interact with your funds. Once you give that permission, the damage is already done. Drainers mostly go after blockchains that support smart contracts. That means they target users on Ethereum and Ethereum-like networks, such as Base, Polygon, and Optimism. But don’t think Ethereum is the only battlefield. Drainers built for Solana exist too, and a drainer aimed at Bitcoin has already made an appearance.

Imagine you want to connect your MetaMask wallet to some project’s website because you’re hoping to grab a little free crypto. Maybe you want to buy a brand-new token while it’s still cheap, before the price shoots up. You click Connect, you type in your password, and you sign a transaction that approves access to your wallet. And that, right there, is exactly the moment a drainer catches you. Instead of a legitimate contract that would let you receive tokens, the hacker gets you to sign a malicious smart contract. In doing so, you unknowingly grant permission for your funds to be transferred out. In effect, you agree, with your own hand, to give away all your money.

So how does a hacker actually pull this off? It works best with something called an airdrop, which is simply a giveaway of new tokens. Airdrops attract a swarm of people who are hoping to get a little bit of crypto that might grow tens of times in value down the road. These giveaways do genuinely happen sometimes, as a real way to promote a new token. So people have learned to trust them. In that exact moment, the user is driven by something we call FOMO, the fear of missing out on a gain.

In their rush to grab the airdrop, a person often doesn’t stop to check who actually created the page they are interacting with, or what the smart contract they are approving actually does under the hood. The website itself might be a perfect copy of the real one, built by the hacker down to the smallest detail, while the smart contract underneath does the opposite of what it promises. Instead of giving you money, it takes it.

Drainers Are Gaining Momentum

In 2024, drainers overtook ordinary ransomware, both in how far they spread and in how much money they brought in. Now, don’t get it wrong, ransomware is still very much the scourge of large businesses. But scammers, being the opportunists they are, have rushed into this new and still relatively uncrowded niche. The very first drainers spread quietly, as scripts traded on darknet marketplaces. Back in 2022 there were 55 unique forums where you could find drainers being sold or discussed. By 2024, that number had jumped to 129 such places, more than double in just two years.

And keep in mind, that count only covers a place as niche and honestly as sparse as the dark web. Most of the real action these days happens on Telegram and Discord.

The biggest drainers active in 2024 had names like Angel, Inferno, Ping, Ace, Cerberus, Nova, Medusa, MS, CryptoGrab, and Venom. Of that whole list, mainly Angel and Ace are still active today, but a new player has stepped onto the stage, one called Vanilla. It hasn’t been studied very closely yet, because it runs on a private model that is difficult for the average scammer to even get access to.

According to Scam Sniffer, a company that closely analyzes different types of crypto fraud, total losses from drainers in 2024 added up to $494.000.000.

That figure only counts the large-scale hacks that could actually be tallied and confirmed. Since drainers mostly target ordinary, everyday users, small thefts of just a few thousand dollars here and there don’t even make it into that statistic. So the real number is almost certainly much higher. 

Among the large-scale cases recorded in 2024, there were more than three hundred thirty thousand victims. The single biggest theft that year came to $55.000.000. All together, there were roughly thirty major fraudulent campaigns, which is one and a half times more than the year before, in 2023. In the first quarter of 2024 alone, drainers showed almost sixfold growth. Compare that to ransomware, which only doubled over that same stretch of time.

So what do all these numbers really mean? Well, because the barrier to entry into this line of work is so remarkably low, it has started attracting scammers who used to work in more old-fashioned territory, like email phishing, luring victims to fake bank login pages and other traditional scam types. A couple of months of this kind of work could buy an apartment, a car, and regular vacations somewhere warm like Thailand. Take one risk, and you can just walk away, or so the thinking goes. But of course, once someone gets a real taste of easy money like that, nobody actually walks away after two months. The business pulls them back in.

Think about the contrast here. A ransomware group has to negotiate with a company, arrange for payment, and handle the whole business of decryption afterward. That’s a lot of hassle and a lot of steps where things can go wrong. A drainer, on the other hand, just steals the money immediately. No negotiation needed. 

Like plenty of other kinds of scams out there, drainers are distributed under what’s called a SaaS model, short for Software-as-a-Service. In this criminal corner of the internet, they’re called DaaS, meaning Drainer-as-a-Service.

There’s also a very characteristic division of labor inside these operations. You’ve got developers, who build the actual malware. You’ve got workers, the rank-and-file operatives out doing the scamming day to day. And alongside them you’ve got recruiters, traffic-generation specialists, and providers of various supporting services that keep the whole machine running. The main job, naturally, falls to the developers. They are the ones who create the malicious software and work to make it more convenient to use, easier to deploy, and easier to scale up. 

How the “Company” Is Built

So what does a hacker actually need in order to pull off a phishing campaign like this?

First, they need domains for their future sites, and these domains are usually spelled just similarly enough to the name of the real project they’re impersonating, so a distracted eye won’t catch the difference. Then they need hosting, which is simply a place to put the site once it’s built. Naturally, they also need a landing page, one designed to closely resemble the legitimate project’s real page. Underneath that landing page sits the drainer code itself, which is typically JavaScript code hosted directly on the site. On top of all that, they’ll usually build a control panel that shows them how many users have been lured in and tracks how those users are behaving on the page. And finally, hackers take their own security seriously too, relying on VPNs, proxies, and fake sockpuppet accounts to cover their tracks.

Professional hackers usually go a step further and set up a full command-and-control server, which lets them manage the drainer’s behavior remotely and adjust it on the fly.

Once all of that infrastructure is in place, all that’s left is bringing in people, actual victims to walk through the trap. That job falls to traffic arbitrage specialists, sometimes called traffic drivers. Their whole task is to funnel users toward the phishing page. They accomplish this in all sorts of ways, everything from buying Google ads to jumping directly into comment sections and posts to engage with real users. Some scammers even go so far as to clone the official support channels of legitimate projects, so a victim reaching out for help ends up talking to the scammer instead.

Put it all together, and what you get is a genuine sales funnel, a designed path that walks victims toward the trap, just like any legitimate marketing funnel would walk a customer toward a purchase.

How the Money Is Split

Here’s how the profits typically get divided up. Operators, the people running the overall scheme, take home twenty to thirty percent of whatever gets stolen. The rest goes to the workers, the people directly out there scamming victims day to day. A worker’s exact cut depends on their skill level. Beginners give up thirty percent of their take to the operators, while the most experienced workers only give up ten to fifteen percent.

And how is a worker’s skill level judged? Simply by how much they have already managed to steal over time. If you’ve stolen up to $10.000 total, you’re considered a beginner. Between $25.000 and $30.000 puts you at mid-level. And starting from $100.000, usually climbing toward a million or more, you’re considered a true professional in this dark little trade.

Driving Traffic

Knowledge in this underground world gets passed around among workers through tutorials. A tutorial itself becomes an item that gets bought, sold, and traded, almost like a piece of merchandise. Entire communities have formed just to gain access to these tutorials, treating them like valuable trade secrets. The writing style of these tutorials makes it fairly clear that AI tools were used to help put them together.

Broadly speaking, the same traffic-driving scheme used in ordinary, everyday phishing applies here too, just adapted for the world of crypto. A worker is essentially doing the same job as any online advertising specialist would. Their goal is simply to increase the number of people clicking through to the phishing page. That means hunting for users who are genuinely interested in Web3 and DeFi projects, people who hold crypto wallets and who are drawn to airdrops, token swaps, and exchanges.

This whole process involves demographic analysis and geolocation analysis, essentially the same ordinary targeting techniques that any advertiser in any industry would recognize. Workers also handle what they call “site design,” which really just means cloning the pages of existing, trusted projects. They’ll even use classic marketing techniques like A/B testing to see which fake page tricks more people.

Now let’s walk through a few high-profile examples of drainer thefts.

The Attack on Arkham Intelligence

Arkham is a company that provides on-chain analytics, and it’s a genuinely popular tool for tracking transactions. Traders rely on it, for instance, to check an asset’s price and see exactly where it’s trading across different platforms.

Back in 2023, Arkham’s owners launched their own token along with an airdrop of coins to celebrate. But hackers saw an opportunity and created numerous fake profiles on X specifically to redirect users toward phishing pages containing a drainer. Remarkably, these bot accounts proved quite resilient and managed to avoid being banned for a long stretch of time. They mimicked Arkham’s real activity closely and spread malicious links far and wide.

A huge number of these fake sites were created during the campaign, and each one typically had a lifespan of just weeks, or a couple of months at most. Angel’s software allowed a hacker to copy landing pages quickly and place them on brand-new domains almost instantly. The whole process has been simplified so much that a worker only needs to type a few commands into a conversation with a Telegram bot in order to deploy an entirely new phishing site.

The Attack on the SEC

An even bigger impact can be achieved by a hacker hijacking the real, verified account of some authoritative company, or even a government organization.

And that’s what happened with the United States Securities and Exchange Commission, or the SEC. On January 9, 2024, its account on X was compromised through a technique called SIM swapping, which basically means reissuing a SIM card tied to the phone number linked to that account. Officials, unfortunately forgetting about basic security hygiene, hadn’t even enabled multi-factor authentication on the account.

Lately, the SIM-swapping community and the drainer community have grown noticeably closer, almost like two neighboring criminal industries starting to collaborate. Swappers now routinely supply drainers with freshly hijacked accounts to use.

The hackers behind this attack posted that the SEC had officially approved investing in Bitcoin without needing to buy crypto directly on an exchange like Binance or Coinbase. This caused an immediate stir, because investors had been waiting a long time for exactly this kind of decision from the SEC, and many expected it to be announced any day. Following the fake post, the hackers urged people to claim an “official SEC airdrop” on a special site that contained a drainer.

That single fake post even caused a real spike in Bitcoin’s price. It rose by a full thousand dollars, just from a fake tweet.

Scamming the Scammers

Scammers, as it turns out, wouldn’t really be scammers if they didn’t also scam each other. At one point, the developer behind the Pink Drainer felt like he was getting close to being unmasked, so he decided to get out of the game entirely and cash out his loot. Here’s the catch, though. You can’t just sell crypto obtained through a scam outright. To actually withdraw the funds, a scammer first has to launder the money, or else an exchange might get suspicious and freeze it before it ever reaches a real bank account.

To avoid enabling things like terrorism financing, or simply to stay within the law, exchanges use a system of scoring and refuse to accept “dirty” crypto. This scoring system is called an AML score, short for anti-money-laundering. There are plenty of laundering methods out there, and while trying one of them, Pink Drainer’s own developer ended up getting scammed himself.  He fell for one of the simplest kinds of fraud imaginable called address poisoning. 

Here’s how it works. Hackers generate crypto addresses that closely resemble a victim’s real address, and then they send that victim a tiny amount of crypto, just enough so that the lookalike address shows up in the victim’s transaction history.

From the user’s side, here’s what it looks like in practice. You send, say, one hundred dollars to some other wallet, maybe an exchange you use regularly. Then, five or ten minutes later, you receive a few tiny transfers that appear to come from that very same wallet. But in reality, they only come from a similar-looking address, one that might share, say, an identical start and end to the real address, while the middle is different.

The hacker is betting that on your next transfer, you’ll simply scroll through your history, pick the most recent address you see, and send your money not back to yourself, but straight into the hacker’s pocket. And that’s exactly how Pink Drainer got caught in his own kind of trap. He picked what looked like the last transaction in his history and sent ten ETH, worth about $15.000 at the time, straight to some unknown “colleague” who was never really his colleague at all.

Conclusion

Because draining is so easy and profitable, this type of scam is not going away anytime soon. If anything, the ways malicious payloads get delivered will only keep getting more sophisticated from here. Drainers are increasingly setting their sights on younger blockchains too. On Ethereum-based networks, it’s steadily getting harder for hackers to operate, since protective measures keep appearing that they have to find new ways to bypass. On Solana, though, no such protections really exist yet, which makes it a much softer target. New kinds of drainers will keep emerging as well. Some scammers have already started building actual apps for Google Play and the App Store, moving beyond simple websites and into places millions of people trust by default. So stay alert out there, and think twice before you click any button, especially one promising you free money. If it feels too good to be true, in crypto more than almost anywhere else, it usually is.

If you’re interested in cryptocurrency forensics, we have a dedicated training called Bitcoin and Cryptocurrency Forensics. You will get to dive into blockchain analysis and cryptocurrency investigations, learning the skills needed to become a cryptocurrency forensic analyst. You can buy the training separately or attend it live on September 15-17 at 3 PM UTC.

The post Cryptocurrency Drainers: How Hackers Steal Cryptocurrency first appeared on Hackers Arise.