Wallet drainer
A wallet drainer is a malicious script on a phishing site that tricks you into signing a transaction or approval, then empties everything valuable from your wallet.
How it works
A drainer does not steal your seed phrase. It hides on a fake airdrop page, an NFT mint or a clone of a known DeFi app. You connect your wallet, the script checks which tokens and NFTs you hold, and it puts in front of you whatever signature benefits the thief most.
Usually that is an approve or a blanket NFT approval, a permit signature that looks like a harmless message, or a direct transfer dressed up as "claim reward". One signature and the tokens go to the scammer's address within seconds. Drainers are sold as a service, so there are a lot of these sites.
Links spread through hacked project accounts, search ads, DMs and replies. A hardware wallet does not save you automatically, because it signs whatever you confirm. What helps is a separate "burner" wallet with a small balance and carefully reading what you sign.
You see a "Claim your airdrop" post from an account that looks like a well-known project. You connect a wallet with 2 ETH and some NFTs and sign "Claim". It was actually approval over all your tokens and NFTs. Thirty seconds later the wallet is empty. With a separate wallet holding $50, you would have lost $50.
The main mistake is connecting your main wallet to any site from an ad, DM or reply and signing everything because "it's free". Use a separate wallet for new sites, check the domain, and if your wallet warns about an approval, Permit or setApprovalForAll, reject it until you understand it. If you signed something bad, revoke approvals at once and move what is left to a new wallet.
Questions and answers
What is a wallet drainer in simple terms?
It is a malicious site that asks you to sign a harmless-looking action that actually gives it the right to take your tokens and NFTs.
What should I do if I signed on a drainer site?
Revoke all approvals right away with an approval checker and move the remaining funds to a new wallet with a new seed phrase. Stolen funds are almost never recovered.
Can a drainer steal funds if I only connected my wallet?
Connecting alone spends nothing, but the site sees your address and holdings. The danger starts with a signature, so do not sign anything on a connected site without reading it.
Related terms
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Updated: 2026-10-19