Most Ethereum scams do not break the network. They trick you into approving them. The common thread is a permission you grant: a token approval, an off-chain signature, or a wallet delegation. Once you sign the wrong one, an attacker can move your funds without asking again. Knowing what you are signing is the core defense.
What makes Ethereum scams different from generic crypto scams?
The difference is the approval model. On Ethereum, apps do not take your tokens directly. Instead, you grant a smart contract permission to move them on your behalf. Scammers exploit that permission system, so the most damaging Ethereum scams happen at the moment you approve or sign something, not when you connect a wallet.
This matters because it changes where the risk lives. Generic crypto scams, like fake giveaways, romance schemes, or rug pulls, work on almost any network and rely on social pressure. Those are covered in our broader academy material on phishing, wallet drainers, and rug pulls. This guide stays on the Ethereum-specific machinery: token approvals, signed messages, and a newer feature called account delegation. Each is a normal, useful part of how Ethereum works. Each can also be turned against you if you approve the wrong contract.
The practical takeaway is simple. Connecting your wallet to a site is usually low risk on its own. Connecting lets a site see your public address. It does not let the site move your funds. The danger begins when a pop-up asks you to approve a token or sign a message. That is the step attackers need, and it is the step worth slowing down for every time.
How do token-approval scams work on Ethereum?
A token-approval scam tricks you into granting a malicious contract permission to spend your tokens, then drains them later. Ethereum tokens use an approval system: before an app can move your USDC or other tokens, you sign an approval that sets how much it may spend. Scammers get you to approve their contract for an unlimited amount, then sweep those tokens whenever they choose.
Here is the mechanic in plain terms. An ERC-20 token approval calls a function named approve, which sets an allowance for a spender (source: Ethereum token approvals, Ledger). A legitimate app asks for only what it needs. A malicious one asks for the maximum possible amount, so it can take everything in that token, now or months later. The approval looks routine in the wallet pop-up, which is exactly why it works. Picture approving a fake trading site to spend your stablecoins. Nothing leaves your wallet at that instant. The theft happens later, when the attacker calls the contract and pulls the full balance.
NFTs have their own version. A function called setApprovalForAll can hand over an entire NFT collection in a single approval (source: Approvals and security, ethereum.org). Scammers use it on fake mint or marketplace sites. The defense is the same for both. Treat every approval as a real permission, not a formality. Approve only known apps, prefer a limited amount over unlimited where your wallet allows it, and review the approvals you have already granted. Knowing how a wallet holds and authorizes your assets helps here, which our guide to how crypto wallets work explains.
What is signature phishing, and why is it so dangerous?
Signature phishing tricks you into signing an off-chain message that authorizes a transfer, rather than a normal transaction. It is dangerous because the signature never appears in your transaction history, and many users assume that signing a message is harmless. It is not. The wrong signed message can be as costly as handing over an approval.
The mechanism uses a feature called Permit. A Permit, and the related Permit2 system, lets you approve token spending by signing a message instead of sending an on-chain transaction (source: Signature phishing, MetaMask). That is convenient for real apps, because it can save a step and a fee. But the signed message is a valid permission. An attacker who collects it can submit it later and move your tokens. Because you only signed, not sent, nothing shows up on-chain at the time, so the warning signs you might look for never appear.
This is why the rule "only a transaction can cost me money" is wrong on Ethereum. A signature can authorize spending just as a transaction can. From Blofin's operational perspective, this is the gap that catches careful users: they refuse risky transactions but sign messages without reading them. Slow down when a site asks for a signature. Check what token and what amount the message authorizes, and whether you recognize the app. If a request to "verify" or "claim" pushes you to sign something you do not understand, treat it as a red flag and stop.
How are scammers abusing EIP-7702 delegation?
EIP-7702 is a 2025 Ethereum feature that lets a normal wallet act like a smart contract by delegating to one. It is useful for letting wallets batch actions and cover fees. Scammers abuse it by tricking users into delegating to a malicious contract, which can then move funds with fewer prompts than a one-off approval would need.
The feature arrived with the Pectra upgrade in May 2025 (source: EIP-7702, Ethereum Improvement Proposals). A standard Ethereum account, called an externally owned account, can now point to contract code and behave like a smart account. That delegation stays in place until you change or remove it, so a bad delegation does not expire on its own. In a scam, the attacker gets you to delegate to a contract they control. Once delegated, that contract can carry out actions on your account, which is how a single bad approval turns into a wider drain. Worse, the delegation can keep draining tokens you receive later, so the fix is to reset it to none through trusted wallet software, not just to empty the wallet.
The early record shows why caution matters. Researchers reported real losses from this method within months of its launch, including a single victim who lost about one and a half million dollars after signing a malicious delegation (source: EIP-7702 phishing loss, Cryptopolitan). Scam-tracking firms also warned that many early delegations pointed to scam-linked contracts rather than to legitimate apps. The red flags are clear once you know them. Be wary if a site asks you to "upgrade" your wallet, set a delegation, or approve a contract you cannot identify. A delegation is a powerful permission. Only grant it through wallet software and apps you trust.
What other Ethereum-specific tricks should you watch for?
Beyond approvals, signatures, and delegation, three tricks show up often on Ethereum: fake airdrops, malicious contract interactions, and address poisoning. Each one steers you toward signing something harmful or sending funds to the wrong place. All three are avoidable once you know the pattern.
Fake airdrops are a common vector. A site promises free tokens, but claiming the reward requires you to connect and sign. The claim button is really an approval or signature request that hands over your tokens. Off-chain Permit-style signatures were the costliest attack type in 2025, behind 38 percent of thefts over one million dollars, according to Scam Sniffer (source: 2025 phishing report, CoinCentral). Malicious contract interactions work similarly. A fake app presents a transaction that looks normal but routes your tokens to the attacker. The fix is to verify the app and read what each request actually does.
Address poisoning is sneakier. An attacker sends you a tiny transaction from an address that looks almost identical to one you use often, hoping you later copy it from your history and send funds to it by mistake. In one case in December 2025, a single address-poisoning theft reached about fifty million dollars after the victim copied a spoofed lookalike address from their history (source: Address-poisoning theft, CoinDesk). The defense is to never copy an address from your transaction history. Save trusted destinations as named contacts, or verify the full address character by character, and use a wallet or block explorer that highlights mismatched addresses. Recognizing too-good-to-be-true offers is part of avoiding the hype, a habit our guide to crypto narrative traps reinforces.
How do you protect yourself on Ethereum?
Protecting yourself comes down to one habit: understand every approval and signature before you confirm it. Most Ethereum losses need your signature, so a careful pause is your strongest defense. Pair that with a hardware wallet, limited approvals, and a routine for checking what you have already granted, and you remove most of the risk.
A short checklist covers the essentials. Read each wallet pop-up and confirm the token, the amount, and the app before approving. Prefer a limited approval over an unlimited one when your wallet offers the choice. Treat signing a message with the same care as sending a transaction, because a Permit signature can move funds. Never approve a delegation or "wallet upgrade" you did not start yourself. And never copy a recipient address from your transaction history, to sidestep address poisoning. For storing the keys that sign all of this, a hardware wallet guide walks through the safest setup, and our explainer on self-custody covers the responsibility that comes with holding your own assets.
It also helps to review and remove old approvals. Approval-checker tools let you see every spending permission your address has granted and revoke the ones you no longer use, which shrinks what any single scam can take. Our broader academy material on revoking token approvals and spotting wallet drainers covers that step in detail. From Blofin's operational perspective, the users who avoid trouble are not the most technical. They are the ones who slow down at the signature screen and ask what a request really wants. There is encouraging news in the data. Scam Sniffer reported that crypto phishing losses fell to about eighty-four million dollars in 2025, down roughly eighty-three percent from the year before, though the drainer ecosystem remains active (source: Phishing losses plunge in 2025, crypto.news). The threat is shrinking, but it has not gone away, so the habits still matter.
Frequently asked questions
Can someone steal my crypto just because I connected my wallet?
Connecting alone is usually low risk. Connecting a wallet to a site lets it see your public address and balances, but it cannot move your funds on its own. The theft happens at the next step, when you approve a token, sign a message, or set a delegation. That signed permission is what an attacker actually needs. So the safe habit is not to fear connecting, but to read and understand every approval or signature request that follows, and to reject anything you do not recognize or cannot explain to yourself.
What is an unlimited token approval, and should I avoid it?
An unlimited approval lets an app spend as much of one token as it wants, with no cap, until you revoke it. Apps sometimes request it for convenience, so you do not have to re-approve later. The risk is that if the app is malicious or is later compromised, it can take your entire balance of that token. Where your wallet lets you set a specific amount instead, that is the safer choice. Either way, review your approvals from time to time and remove the ones you no longer use, so a single bad permission cannot drain everything.
Is signing a message safer than approving a transaction?
No, and this is a common and costly misunderstanding. On Ethereum, a signed message can authorize someone to move your tokens, using a feature called Permit. The signature does not appear on-chain when you sign it, so it can feel harmless, but an attacker can submit it later and take funds. Treat a signature request with the same caution as a transaction. Check what token and amount it covers and whether you trust the app. If a "verify" or "claim" prompt asks you to sign something you do not understand, stop.
How do I check and remove the approvals I have given?
Approval-checker tools let you connect your address and see every spending permission you have granted, then revoke the ones you no longer need. Removing unused approvals limits what any single scam or compromised app can take. It is good practice to do this every so often, and especially after using a new app or claiming any airdrop. Our broader academy guides on revoking token approvals walk through the exact steps. The general principle is to keep your active permissions short, recognized, and limited in amount wherever possible.
Are hardware wallets enough to stop approval scams?
A hardware wallet helps, but it is not a complete shield against this kind of scam. It protects your private keys by keeping them offline, which stops attackers who try to steal the keys directly. But if you approve a malicious contract or sign a harmful Permit message, the hardware wallet will sign exactly what you confirmed. So the device protects the keys, while you protect the permissions. Use both together: store keys on a hardware wallet, and still read every approval and signature carefully before you confirm it.
Did Ethereum scams get better or worse recently?
They eased in 2025 but did not disappear. Scam Sniffer reported that crypto phishing and drainer losses fell to around eighty-four million dollars in 2025, down roughly eighty-three percent from the prior year, with far fewer victims. Losses still spiked during market rallies, and new methods like EIP-7702 delegation phishing emerged, so the drainer ecosystem stayed active. The honest read is that the problem is shrinking but evolving. The defensive habits in this guide, especially reading what you sign, remain the most reliable protection regardless of the yearly totals.
Researched and written by the Blofin Academy editorial team with AI-assisted drafting. Primary sources include the Ethereum Improvement Proposals (EIP-7702) and the Ethereum.org security documentation. Attack mechanics and 2025 loss data were cross-checked against MetaMask, Ledger, Scam Sniffer via CoinCentral, CoinDesk, crypto.news, and Cryptopolitan, and independently verified against cited sources current as of June 2026.
This article is for informational purposes only and is intended to help readers recognize and avoid scams. It does not constitute financial advice, investment guidance, or a recommendation to buy, sell, or hold any digital asset. Attack methods, loss figures, and tools change frequently and are approximate ranges current as of 2025 and 2026; verify current guidance before acting. Cryptocurrency markets involve significant risk, and you should do your own research and consult qualified professionals before making decisions. Blofin Academy content reflects the state of public information at time of publication; protocol parameters, fees, and ecosystem data change frequently.