What it looks like
You connect your wallet to a site offering a giveaway, an airdrop or a "verification". It asks you to sign a transaction. Instead of a small transfer, the signature grants unlimited permission to spend a token. Later, sometimes days later, the token is moved out of your wallet.
Red flags
- A site asks you to connect your wallet to claim something free.
- The wallet prompt mentions "approve", "setApprovalForAll" or an unlimited amount.
- The site was shared by a new account or in a direct message.
What to do next
- Review and revoke approvals you don't recognise using a reputable approval checker.
- Move remaining funds to a fresh wallet if you're unsure what you signed.
- Keep the transaction hashes and start a free assessment if you've lost crypto.