Crypto is self-custodial by design. That’s the feature. But this foundational attribute, which is core to the values of the industry, can often make you the user a single point of failure. In many cases of individuals losing their funds in crypto, it’s not a bug in the protocol: it’s a click. A DM. An approval. A moment of trust or carelessness performing a seemingly non-consequential everyday task that can alter the course of one’s crypto experiences.
This report is not a technical whitepaper or a review of smart contract logic but rather a threat model for individuals. A breakdown of how users get exploited in practice, and what to do about it. The report will focus on personal-level exploits: phishing, wallet approvals, social engineering, malware. It will also briefly cover protocol-level risks at the end to give a layout of the spectrum of exploits that happen in crypto.
The permanent and irreversible nature of transactions that happen in permissionless settings, often without the say of intermediaries, combined with the fact that individual users are responsible for interacting with anonymous counterparties on the same devices and browsers that hold financial assets, makes crypto a unique hunting ground for hackers and other criminals. Below is an extensive list of the types of exploits individuals can face, but readers should be aware that while this list covers the majority of exploits, it is non-exhaustive. The list may be overwhelming to those not familiar with crypto, but a good portion of these are “regular” exploits that have happened for quite some time in the internet age and are not unique to this industry. §3 will cover a few key exploit methods in detail.
Attacks relying on psychological manipulation to deceive individuals into compromising their security.
Figure 1: The consequences of social engineering can be very severe
Source: Cointelegraph
Exploiting telecom infrastructure or account-level weaknesses to bypass authentication.
Figure 2: A fake Tweet from the SEC via a SIM swap
Source: Twitter
Compromising the user’s device to extract wallet access or tamper with transactions (more in §3).
Figure 3: Fake wallets are a common scam targeting beginner crypto users
Source: cryptorank
Attacks targeting how users manage or interact with wallets and signing interfaces.
Risks stemming from interactions with malicious or vulnerable on-chain code.
Figure 4: A flash loan was responsible for one of DeFi’s largest exploits
Source: Elliptic
Scams tied to the structure of tokens, DeFi projects, or NFT collections.
Exploiting the front-end or DNS-level infrastructure users rely on.
Real-world risks involving coercion, theft, or surveillance.
Figure 5: Unfortunately, physical threats have been common
Source: The New York Times
Some exploits happen more than others. Here are three exploits individuals holding or interacting with crypto should know about, including how to prevent them. An aggregation of prevention techniques and key attributes to watch out for will be listed at the end of the section as there are overlaps amongst the various exploit methods.
Phishing predates crypto by decades and the term emerged in the 1990s to describe attackers “fishing” for sensitive information, usually login credentials, via fake emails and websites. As crypto emerged as a parallel financial system, phishing naturally evolved to target seed phrases, private keys, and wallet authorisations i.e., the crypto equivalents of “full control.”
Crypto phishing is especially dangerous because there’s no recourse: no chargebacks, no fraud protection, and no customer support that can reverse a transaction. Once your key is stolen, your funds are as good as gone. It is also important to remember that phishing is sometimes just the first step in a broader exploit, making the real risk not the initial loss, but the long tail of compromises that follow e.g., compromised credentials can allow an attacker to impersonate the victim and scam others.
How does phishing work?
At its core, phishing exploits human trust by presenting a fake version of a trusted interface, or by posing as someone authoritative, to trick users into voluntarily handing over sensitive information or approving malicious actions. There are several primary delivery vectors:
Figure 6: Always be cautious when you see “free” in crypto
Source: Presto Research
Examples of phishing
The Atomic Wallet hack of June 2023, attributed to North Korea’s Lazarus Group, stands as one of the most destructive pure phishing attacks in crypto history. It led to the theft of over $100 million in cryptocurrency by compromising more than 5,500 non-custodial wallets without requiring users to sign any malicious transactions or interact with smart contracts. This attack focused solely on seed phrase and private key extraction through deceptive interfaces and malware - a textbook example of phishing-based credential theft.
Atomic Wallet is a multi-chain, non-custodial wallet supporting over 500 cryptocurrencies. In this incident, attackers launched a coordinated phishing campaign that exploited the trust users placed in the wallet’s support infrastructure, update processes, and brand identity. Victims were lured through emails, fake websites, and trojanised software updates, all designed to mimic legitimate communications from Atomic Wallet.
The phishing vectors included:
atomic-wallet[.]co
) that mimicked the wallet’s recovery or reward claim interface.Once users entered their 12- or 24-word seed phrases or private keys into these fraudulent interfaces, attackers gained full access to their wallets. This exploit involved no on-chain interaction from the victim: no wallet connection, no signature requests, and no smart contract involvement. Instead, it relied entirely on social engineering and the user’s willingness to restore or verify their wallet on what appeared to be a trusted platform.
A wallet drainer is a type of malicious smart contract or dApp designed to extract assets from your wallet, not by stealing your private key, but by tricking you into authorising token access or signing dangerous transactions. Unlike phishing, which seeks your credentials, drainers exploit permissions - the elemental mechanism of trust that powers Web3.
As DeFi and Web3 apps became mainstream, wallets like MetaMask and Phantom popularised the idea of “connecting” to dApps. This brought convenience but also a massive attack surface. In 2021–2023, approval drainers exploded in popularity through NFT mints, fake airdrops, and rug-pulled dApps began embedding malicious contracts into otherwise familiar UIs. Users, often excited or distracted, would connect their wallet and click “Approve” without realising what they were authorising.
How is this different from phishing?
Phishing involves tricking someone into voluntarily revealing sensitive credentials, such as a seed phrase, password, or private key. Connecting your wallet doesn’t reveal your keys or phrases as you’re not handing over secrets, you’re signing transactions or granting permissions. These exploits occur through smart contract logic, not theft of your credentials, making them mechanically different from phishing. You’re authorising the drain, often without realising it, which is more like a “consent trap” than credential theft.
You can think of phishing as CREDENTIALS-BASED and wallet drainers / malicious approvals as PERMISSION-BASED.
The mechanics of the attack
Malicious approvals exploit the permission systems in blockchain standards like ERC-20 (tokens) and ERC-721/ERC-1155 (NFTs). They trick users into granting attackers ongoing access to their assets.
Examples of wallet drainers / malicious approvals
The Monkey Drainer scam, active primarily in 2022 and early-2023, was a notorious “drainer-as-a-service” phishing toolkit responsible for stealing millions in crypto (including NFTs) through deceptive websites and malicious smart contracts. Unlike traditional phishing, which relies on harvesting user seed phrases or passwords, Monkey Drainer operated through malicious transaction signatures and smart contract abuse, enabling attackers to extract tokens and NFTs without direct credential compromise. By tricking users into signing dangerous on-chain approvals, Monkey Drainer enabled over $4.3 million in theft across hundreds of wallets before its shutdown in early-2023.
Figure 7: Famous on-chain detective ZachXBT uncovers Monkey Drainer scams
Source: Twitter (@zachxbt)
The kit was popular among low-skill attackers and heavily marketed in underground Telegram and dark web communities. It allowed affiliates to clone fake mint sites, impersonate real projects, and configure the backend to forward signed transactions to a centralised draining contract. These contracts were engineered to exploit token permissions, relying on users to unwittingly sign messages that granted the attacker’s address access to assets via functions like setApprovalForAll() (NFTs) or permit() (ERC-20 tokens).
Notably, the interaction flow avoided direct phishing: victims were not asked for their private keys or seed phrases. Instead, they engaged with seemingly legitimate dApps, often on minting pages with countdowns or hyped branding. Once connected, users would be prompted to sign a transaction they didn’t fully understand, often masked by generic approval language or wallet UI obfuscation. These signatures did not transfer funds directly, but authorised the attacker to do so at any time. With permissions granted, the drainer contract could execute batch withdrawals in a single block.
A hallmark of the Monkey Drainer method was its delayed execution: stolen assets were often drained hours or days later, to avoid suspicion and maximise yield. This made it particularly effective against users with large wallets or active trading activity, whose approvals blended into normal usage patterns. High-profile victims included NFT collectors who lost assets from projects like CloneX, Bored Apes, and Azuki.
Although Monkey Drainer ceased operations in 2023, presumably to “lay low” the era of wallet drainers continues to evolve, posing a persistent threat to users who misunderstand or underestimate the power of an on-chain approval.
Finally, ‘malware and device exploits’ refer to a broad, versatile range of attacks that encompass various delivery vectors which all aim to compromise a user’s computer, phone, or browser, typically through malicious software installed via deception. The goal is usually to steal sensitive information (e.g. seed phrases, private keys), intercept wallet interactions, or give the attacker remote control of the victim’s device. In crypto, these attacks often begin with social engineering, such as a fake job offer, a bogus app update, or a file sent via Discord, but quickly escalate into full-scale system compromise.
Malware has existed since the early days of personal computing. In traditional contexts, it was used to steal credit card info, harvest logins, or hijack systems for spam or ransomware. As crypto gained traction, attackers pivoted: instead of targeting credentials for online banking (which can be reversed), they now aim to steal irreversible crypto assets.
How These Attacks Start… The Social Engineering Angle
Most malware doesn’t spread randomly: it requires the victim to be deceived into executing it. This is where social engineering comes in.
Common Delivery Methods:
The common thread: The attacker creates a believable context that convinces the user to click, download, or open something dangerous.
Types of Malware Common in Crypto Exploits
Example: The 2022 Axie Infinity Job Scam
The Axie Infinity job scam of 2022, which led to the massive Ronin Bridge hack, is a prime example of a malware and device exploit in the crypto space, driven by sophisticated social engineering. This attack, attributed to the North Korean state-sponsored Lazarus Group, resulted in the theft of approximately $620 million in cryptocurrency, making it one of the largest decentralised finance (DeFi) hacks to date.
Figure 8: The Axie Infinity exploit made it to TradFi media
Source: Bloomberg TV
The hack was a multi-stage operation combining social engineering, malware deployment, and exploitation of blockchain infrastructure vulnerabilities.
The hackers, posing as recruiters from a fictitious company, targeted Sky Mavis employees through LinkedIn: Sky Mavis is the company behind the Ronin Network, an Ethereum-linked sidechain powering Axie Infinity, a popular play-to-earn blockchain game. At the time, Ronin and Axis Infinity had respective market caps of around $300 million and $4 billion.
Multiple employees were approached, but a senior engineer became the primary target who the attackers conducted multiple rounds of fake job interviews with to build trust, offering an extremely generous compensation package to lure the engineer. The attackers sent a PDF document, disguised as a formal job offer, to the engineer. The engineer, believing it was part of the hiring process, downloaded and opened the file on a company computer. The PDF contained a RAT which infected the engineer’s system upon opening, granting hackers access to Sky Mavis’ internal systems, likely through privilege escalation or lateral movement within the network. This compromise provided a foothold to target the Ronin Network’s infrastructure.
The mechanics of the hack which continued to exploit the Ronin bridge and the Axie DAO is beyond the scope of this research article, however, this exploit resulted in a $620 million theft (173,600 ETH and 25.5MM USDC) with only $30 million recovered.
Exploit attempts are increasingly sophisticated, but still rely on telltale signs. Red flags include:
Further OpSec (operational security) rules:
Most users think of exploits in crypto as something technical and unavoidable, particularly those new to the industry. While that may be true for complex attack methods, oftentimes the initial step targets the individual in non-technical ways, making the rest of the exploit preventable.
The vast majority of personal losses in this space don’t come from some novel zero-day or obscure protocol bug but rather from people signing things they didn’t read or importing wallets into fake apps, or trusting a DM that feels just plausible enough. The tools might be new, but the tactics are as old as time: deception, urgency, misdirection.
People come to crypto for the self-custody and the permissionless nature, but users need to remember that here the stakes are higher; in traditional finance, you get scammed and you call the bank. In crypto, you get scammed and that’s the end of the story.
Crypto is self-custodial by design. That’s the feature. But this foundational attribute, which is core to the values of the industry, can often make you the user a single point of failure. In many cases of individuals losing their funds in crypto, it’s not a bug in the protocol: it’s a click. A DM. An approval. A moment of trust or carelessness performing a seemingly non-consequential everyday task that can alter the course of one’s crypto experiences.
This report is not a technical whitepaper or a review of smart contract logic but rather a threat model for individuals. A breakdown of how users get exploited in practice, and what to do about it. The report will focus on personal-level exploits: phishing, wallet approvals, social engineering, malware. It will also briefly cover protocol-level risks at the end to give a layout of the spectrum of exploits that happen in crypto.
The permanent and irreversible nature of transactions that happen in permissionless settings, often without the say of intermediaries, combined with the fact that individual users are responsible for interacting with anonymous counterparties on the same devices and browsers that hold financial assets, makes crypto a unique hunting ground for hackers and other criminals. Below is an extensive list of the types of exploits individuals can face, but readers should be aware that while this list covers the majority of exploits, it is non-exhaustive. The list may be overwhelming to those not familiar with crypto, but a good portion of these are “regular” exploits that have happened for quite some time in the internet age and are not unique to this industry. §3 will cover a few key exploit methods in detail.
Attacks relying on psychological manipulation to deceive individuals into compromising their security.
Figure 1: The consequences of social engineering can be very severe
Source: Cointelegraph
Exploiting telecom infrastructure or account-level weaknesses to bypass authentication.
Figure 2: A fake Tweet from the SEC via a SIM swap
Source: Twitter
Compromising the user’s device to extract wallet access or tamper with transactions (more in §3).
Figure 3: Fake wallets are a common scam targeting beginner crypto users
Source: cryptorank
Attacks targeting how users manage or interact with wallets and signing interfaces.
Risks stemming from interactions with malicious or vulnerable on-chain code.
Figure 4: A flash loan was responsible for one of DeFi’s largest exploits
Source: Elliptic
Scams tied to the structure of tokens, DeFi projects, or NFT collections.
Exploiting the front-end or DNS-level infrastructure users rely on.
Real-world risks involving coercion, theft, or surveillance.
Figure 5: Unfortunately, physical threats have been common
Source: The New York Times
Some exploits happen more than others. Here are three exploits individuals holding or interacting with crypto should know about, including how to prevent them. An aggregation of prevention techniques and key attributes to watch out for will be listed at the end of the section as there are overlaps amongst the various exploit methods.
Phishing predates crypto by decades and the term emerged in the 1990s to describe attackers “fishing” for sensitive information, usually login credentials, via fake emails and websites. As crypto emerged as a parallel financial system, phishing naturally evolved to target seed phrases, private keys, and wallet authorisations i.e., the crypto equivalents of “full control.”
Crypto phishing is especially dangerous because there’s no recourse: no chargebacks, no fraud protection, and no customer support that can reverse a transaction. Once your key is stolen, your funds are as good as gone. It is also important to remember that phishing is sometimes just the first step in a broader exploit, making the real risk not the initial loss, but the long tail of compromises that follow e.g., compromised credentials can allow an attacker to impersonate the victim and scam others.
How does phishing work?
At its core, phishing exploits human trust by presenting a fake version of a trusted interface, or by posing as someone authoritative, to trick users into voluntarily handing over sensitive information or approving malicious actions. There are several primary delivery vectors:
Figure 6: Always be cautious when you see “free” in crypto
Source: Presto Research
Examples of phishing
The Atomic Wallet hack of June 2023, attributed to North Korea’s Lazarus Group, stands as one of the most destructive pure phishing attacks in crypto history. It led to the theft of over $100 million in cryptocurrency by compromising more than 5,500 non-custodial wallets without requiring users to sign any malicious transactions or interact with smart contracts. This attack focused solely on seed phrase and private key extraction through deceptive interfaces and malware - a textbook example of phishing-based credential theft.
Atomic Wallet is a multi-chain, non-custodial wallet supporting over 500 cryptocurrencies. In this incident, attackers launched a coordinated phishing campaign that exploited the trust users placed in the wallet’s support infrastructure, update processes, and brand identity. Victims were lured through emails, fake websites, and trojanised software updates, all designed to mimic legitimate communications from Atomic Wallet.
The phishing vectors included:
atomic-wallet[.]co
) that mimicked the wallet’s recovery or reward claim interface.Once users entered their 12- or 24-word seed phrases or private keys into these fraudulent interfaces, attackers gained full access to their wallets. This exploit involved no on-chain interaction from the victim: no wallet connection, no signature requests, and no smart contract involvement. Instead, it relied entirely on social engineering and the user’s willingness to restore or verify their wallet on what appeared to be a trusted platform.
A wallet drainer is a type of malicious smart contract or dApp designed to extract assets from your wallet, not by stealing your private key, but by tricking you into authorising token access or signing dangerous transactions. Unlike phishing, which seeks your credentials, drainers exploit permissions - the elemental mechanism of trust that powers Web3.
As DeFi and Web3 apps became mainstream, wallets like MetaMask and Phantom popularised the idea of “connecting” to dApps. This brought convenience but also a massive attack surface. In 2021–2023, approval drainers exploded in popularity through NFT mints, fake airdrops, and rug-pulled dApps began embedding malicious contracts into otherwise familiar UIs. Users, often excited or distracted, would connect their wallet and click “Approve” without realising what they were authorising.
How is this different from phishing?
Phishing involves tricking someone into voluntarily revealing sensitive credentials, such as a seed phrase, password, or private key. Connecting your wallet doesn’t reveal your keys or phrases as you’re not handing over secrets, you’re signing transactions or granting permissions. These exploits occur through smart contract logic, not theft of your credentials, making them mechanically different from phishing. You’re authorising the drain, often without realising it, which is more like a “consent trap” than credential theft.
You can think of phishing as CREDENTIALS-BASED and wallet drainers / malicious approvals as PERMISSION-BASED.
The mechanics of the attack
Malicious approvals exploit the permission systems in blockchain standards like ERC-20 (tokens) and ERC-721/ERC-1155 (NFTs). They trick users into granting attackers ongoing access to their assets.
Examples of wallet drainers / malicious approvals
The Monkey Drainer scam, active primarily in 2022 and early-2023, was a notorious “drainer-as-a-service” phishing toolkit responsible for stealing millions in crypto (including NFTs) through deceptive websites and malicious smart contracts. Unlike traditional phishing, which relies on harvesting user seed phrases or passwords, Monkey Drainer operated through malicious transaction signatures and smart contract abuse, enabling attackers to extract tokens and NFTs without direct credential compromise. By tricking users into signing dangerous on-chain approvals, Monkey Drainer enabled over $4.3 million in theft across hundreds of wallets before its shutdown in early-2023.
Figure 7: Famous on-chain detective ZachXBT uncovers Monkey Drainer scams
Source: Twitter (@zachxbt)
The kit was popular among low-skill attackers and heavily marketed in underground Telegram and dark web communities. It allowed affiliates to clone fake mint sites, impersonate real projects, and configure the backend to forward signed transactions to a centralised draining contract. These contracts were engineered to exploit token permissions, relying on users to unwittingly sign messages that granted the attacker’s address access to assets via functions like setApprovalForAll() (NFTs) or permit() (ERC-20 tokens).
Notably, the interaction flow avoided direct phishing: victims were not asked for their private keys or seed phrases. Instead, they engaged with seemingly legitimate dApps, often on minting pages with countdowns or hyped branding. Once connected, users would be prompted to sign a transaction they didn’t fully understand, often masked by generic approval language or wallet UI obfuscation. These signatures did not transfer funds directly, but authorised the attacker to do so at any time. With permissions granted, the drainer contract could execute batch withdrawals in a single block.
A hallmark of the Monkey Drainer method was its delayed execution: stolen assets were often drained hours or days later, to avoid suspicion and maximise yield. This made it particularly effective against users with large wallets or active trading activity, whose approvals blended into normal usage patterns. High-profile victims included NFT collectors who lost assets from projects like CloneX, Bored Apes, and Azuki.
Although Monkey Drainer ceased operations in 2023, presumably to “lay low” the era of wallet drainers continues to evolve, posing a persistent threat to users who misunderstand or underestimate the power of an on-chain approval.
Finally, ‘malware and device exploits’ refer to a broad, versatile range of attacks that encompass various delivery vectors which all aim to compromise a user’s computer, phone, or browser, typically through malicious software installed via deception. The goal is usually to steal sensitive information (e.g. seed phrases, private keys), intercept wallet interactions, or give the attacker remote control of the victim’s device. In crypto, these attacks often begin with social engineering, such as a fake job offer, a bogus app update, or a file sent via Discord, but quickly escalate into full-scale system compromise.
Malware has existed since the early days of personal computing. In traditional contexts, it was used to steal credit card info, harvest logins, or hijack systems for spam or ransomware. As crypto gained traction, attackers pivoted: instead of targeting credentials for online banking (which can be reversed), they now aim to steal irreversible crypto assets.
How These Attacks Start… The Social Engineering Angle
Most malware doesn’t spread randomly: it requires the victim to be deceived into executing it. This is where social engineering comes in.
Common Delivery Methods:
The common thread: The attacker creates a believable context that convinces the user to click, download, or open something dangerous.
Types of Malware Common in Crypto Exploits
Example: The 2022 Axie Infinity Job Scam
The Axie Infinity job scam of 2022, which led to the massive Ronin Bridge hack, is a prime example of a malware and device exploit in the crypto space, driven by sophisticated social engineering. This attack, attributed to the North Korean state-sponsored Lazarus Group, resulted in the theft of approximately $620 million in cryptocurrency, making it one of the largest decentralised finance (DeFi) hacks to date.
Figure 8: The Axie Infinity exploit made it to TradFi media
Source: Bloomberg TV
The hack was a multi-stage operation combining social engineering, malware deployment, and exploitation of blockchain infrastructure vulnerabilities.
The hackers, posing as recruiters from a fictitious company, targeted Sky Mavis employees through LinkedIn: Sky Mavis is the company behind the Ronin Network, an Ethereum-linked sidechain powering Axie Infinity, a popular play-to-earn blockchain game. At the time, Ronin and Axis Infinity had respective market caps of around $300 million and $4 billion.
Multiple employees were approached, but a senior engineer became the primary target who the attackers conducted multiple rounds of fake job interviews with to build trust, offering an extremely generous compensation package to lure the engineer. The attackers sent a PDF document, disguised as a formal job offer, to the engineer. The engineer, believing it was part of the hiring process, downloaded and opened the file on a company computer. The PDF contained a RAT which infected the engineer’s system upon opening, granting hackers access to Sky Mavis’ internal systems, likely through privilege escalation or lateral movement within the network. This compromise provided a foothold to target the Ronin Network’s infrastructure.
The mechanics of the hack which continued to exploit the Ronin bridge and the Axie DAO is beyond the scope of this research article, however, this exploit resulted in a $620 million theft (173,600 ETH and 25.5MM USDC) with only $30 million recovered.
Exploit attempts are increasingly sophisticated, but still rely on telltale signs. Red flags include:
Further OpSec (operational security) rules:
Most users think of exploits in crypto as something technical and unavoidable, particularly those new to the industry. While that may be true for complex attack methods, oftentimes the initial step targets the individual in non-technical ways, making the rest of the exploit preventable.
The vast majority of personal losses in this space don’t come from some novel zero-day or obscure protocol bug but rather from people signing things they didn’t read or importing wallets into fake apps, or trusting a DM that feels just plausible enough. The tools might be new, but the tactics are as old as time: deception, urgency, misdirection.
People come to crypto for the self-custody and the permissionless nature, but users need to remember that here the stakes are higher; in traditional finance, you get scammed and you call the bank. In crypto, you get scammed and that’s the end of the story.