If you have spent any time in crypto, you have probably seen a wallet popup asking you to sign something before a transaction goes through. Most people click approve without a second thought. On January 3, 2026, that exact habit cost one crypto user $1.08 million. They signed a malicious permit signature that gave an attacker permission to drain their aEthLBTC tokens directly from their wallet. With Bitcoin hovering around $90,600 and the crypto market showing fresh signs of life, understanding what permit signatures are and how they can be weaponized against you is no longer optional knowledge—it is essential for anyone holding digital assets. This guide breaks it all down in plain language.
The Basics
A permit signature is a type of crypto authorization that lets someone else move tokens from your wallet without requiring a separate on-chain approval transaction. It was introduced through a standard called EIP-2612, and it was designed to make using decentralized applications smoother and cheaper. Instead of requiring two transactions—one to approve token spending and another to execute the actual transfer—a permit signature lets you do it all in one step by signing an off-chain message. Think of it like writing a pre-signed check: you fill in the amount and sign it, and whoever holds the check can cash it later without needing any further action from you.
Why It Matters
The problem with permit signatures is that they are incredibly easy to abuse. When you sign a permit, you are granting permission for another address to spend your tokens. If you sign a permit from a malicious source—a fake website, a phishing link in your DMs, or a spoofed decentralized application—you have just given the attacker a blank check to your tokens. The January 3 attack worked exactly this way. The victim thought they were interacting with a legitimate platform, but the signature they signed authorized a complete stranger to transfer their aEthLBTC out of their wallet. Because the signature was technically valid and authorized by the user, there was no protocol to reverse the transaction and no way to recover the funds.
Getting Started Guide
Protecting yourself starts with understanding what you are signing. Every time your wallet prompts you with a signature request, take ten seconds to examine it. Check the application URL carefully—phishers often create domains that look almost identical to legitimate ones, with subtle differences like an extra letter or a different top-level domain. If you are using MetaMask or a similar wallet, look at the decoded signature data. Legitimate requests will show clear information about what you are authorizing. If the data looks like a jumble of hexadecimal characters with no clear explanation, that is a red flag. Install a browser extension like Wallet Guard or Revoke.cash that automatically simulates and decodes signature requests before you approve them. These tools can warn you when a signature request is attempting to authorize unusual spending permissions.
Common Pitfalls
The biggest mistake beginners make is assuming that a hardware wallet protects them from all attacks. Hardware wallets protect your private keys, but they cannot prevent you from signing a malicious transaction. If you plug in your Ledger or Trezor and approve a phishing signature, the hardware wallet will execute it faithfully—because from its perspective, you authorized it. Another common pitfall is ignoring token approvals after completing a transaction. Many users approve unlimited spending caps for convenience, which means that if the approved address is ever compromised, all of your tokens in that contract are at risk. Finally, clicking links from direct messages on Telegram, Discord, or X is one of the fastest ways to encounter a phishing site. Always navigate to decentralized applications manually by typing the URL yourself.
Next Steps
Now that you understand permit signatures and their risks, take immediate action. Visit Revoke.cash and connect your wallet to review all active token approvals. Revoke any approvals you do not recognize or no longer need. Set up a weekly reminder to check your approvals. Consider creating a separate wallet specifically for interacting with new or unfamiliar applications, keeping only the tokens you need for that specific interaction. Stay informed about new phishing techniques by following security researchers on social media. The crypto space evolves quickly, and attackers adapt just as fast. Your best protection is a combination of the right tools, informed habits, and a healthy dose of skepticism every time your wallet asks you to sign something.
Disclaimer: This article is for educational purposes only and does not constitute financial or security advice. Always conduct your own research.
Finally a clear explanation of EIP-2612 that does not require a CS degree. Sharing this with everyone I know in crypto
Bram V. EIP-2612 making signatures gasless was supposed to be a UX win. instead it became the easiest drain vector in defi. every wallet popup is now a potential $1M mistake
been in crypto two years and did not know permit signatures skip the on-chain approval step. scary
The click approve without thinking habit is exactly what got that person for $1.08m. We all do it. Humbling read.
^ honest take. we have all been one wrong click away from disaster at some point
$1.08M gone from one wrong signature. if you are interacting with any DeFi protocol, check the spender address and the amount. takes 10 seconds
aEthLBTC specifically. not a random memecoin. a liquid staking token worth over a million and one signature wiped it. the attacker knew exactly what they were targeting
token_approve_ checking the spender address takes 10 seconds but most people dont even know what to look for. the UX needs to fix this not the user
Wei Tanaka the UX cant fix this alone. wallets need native simulation that shows you exactly what a permit does before you sign. tenderly integration should be default not optional
Wei Tanaka is right that UX cant fix this alone but wallet simulation has gotten way better. Rabby shows you exactly what a permit does before you sign. MetaMask still doesnt and its 2026
Zofia W. Rabby decoding the permit payload before signing should be industry standard. MetaMask still showing hex blobs in 2026 is almost negligent
zofia w. rabby showing exactly what a permit does before signing is table stakes. meta mask not having this in 2026 is almost negligent
$1.08M gone from signing one message. no transaction broadcast, no gas spent, just a signature. most people dont understand the difference between signing and sending
rune_frost the signing vs sending distinction needs to be in every wallet onboarding flow. most users think no gas means no risk. thats the fundamental UX failure
rune_frost signing vs sending is the key distinction most users dont get. you are not paying gas so you think its harmless. thats exactly what the attacker counts on
Bookmarking this. Every DeFi user should understand permit signatures before their next interaction.
EIP-2612 was designed for convenience and it delivered. problem is convenience in crypto always comes with a gun pointed at your wallet
1.08M gone from one permit signature on aEthLBTC. people blindly sign whatever metamask throws at them and this is the result
1.08M gone from one signature. no gas paid, no transaction broadcast, just a signed message. most wallet users dont even know the difference between signing and sending
eip-2612 was supposed to save gas but ended up being the easiest drain vector. use revoke.cash and stop signing blind
EIP-2612 making signatures gasless was a UX win that became the easiest drain vector in DeFi. wallets need native simulation before this gets better
EIP-2612 was designed for convenience but it became the most dangerous UX pattern in DeFi. the tradeoff between gas savings and security is brutal
1.08M from one signature on aethlbtc. that is a liquid staking token, not some random erc20. the attacker knew exactly what to target
Emeka N. targeting aEthLBTC specifically means the attacker knew the victim had a liquid staking position worth over a million. this was reconnaissance not a spray and pray
emeka n. targeting a liquid staking token means the victim was likely an experienced defi user. not a beginner clicking a fake uniswap link