The Problem: Emptied in One Click
You see a post: “Claim your free airdrop before it ends!” You click, connect your wallet, press “Sign,” and see a message about a successful claim. A minute later, every token in your wallet is gone.
You never shared your seed phrase. You never typed a password. So how did it happen? Meet the wallet drainer, one of the most common ways people lose crypto today.
The Blank Check Analogy
Imagine a stranger asks you to sign a form “just to confirm your prize.” You sign without reading it. The form was actually a blank check with permission to take anything from your account.
That’s how a drainer works. It doesn’t break into your wallet. It tricks you into giving permission, and then uses that permission to take everything.
How Wallet Drainers Work
1. The Bait
Drainers hide behind things you want: free airdrops, NFT mints, “claim your rewards” pages, fake versions of popular apps, even sponsored search results and hacked social media accounts.
2. The Connection
You connect your wallet. Just connecting doesn’t let them take anything, but it lets the site see exactly which tokens and NFTs you hold.
3. The Trap Signature
The site asks you to approve or sign something. It looks routine, but it’s really one of these:
- An unlimited token approval, letting their contract move a token for you.
- A “permit” signature, a gas-free message that gives the same permission. It feels harmless because it costs nothing.
- “Approval for all” on NFTs, handing over a whole collection.
4. The Drain
Within seconds, automated scripts use your permission to move everything valuable to the scammer’s wallets.
How Big Is the Problem?
According to the security firm Scam Sniffer, phishing and drainer scams stole about $494 million from over 300,000 victims in 2024. Losses fell to around $84 million in 2025, but the tools are still sold to scammers like a subscription service, and losses rise whenever the market gets busy.
Common Questions, Simple Answers
“Can just visiting a site drain my wallet?”
No. A drainer needs you to sign or approve something. Connecting alone doesn’t move funds, but it’s still wise to avoid shady sites.
“Does a hardware wallet protect me?”
It protects your keys, but if you approve a malicious request on the device, it will sign it. Read the screen before you press confirm.
“Can I get my crypto back?”
Almost never. Blockchain transactions are final. Be very wary of “recovery experts” who contact you afterward: that’s a second scam.
“I signed something suspicious but nothing happened yet. What now?”
Act fast: revoke the approval, then move your funds to a brand-new wallet.
Red Flags of a Drainer Site
- “Free” tokens or NFTs you never signed up for
- A countdown or “only 10 minutes left” pressure
- A link that came from a DM, a reply, or an ad
- A web address that’s slightly off from the real one
- A signature request you don’t understand, especially one that mentions “Permit” or “setApprovalForAll”
The “Aha!” Moment
In crypto, your signature is your wallet’s key. Scammers don’t need to steal your password if you’ll sign the permission yourself. Slow down every time your wallet pops up.
Your Anti-Drainer Action Steps
- Use a Burner Wallet: Keep a separate wallet with a small balance for airdrops, mints and new apps. Keep your savings in a wallet that never connects to anything new.
- Read Before You Sign: If your wallet warns you, stop. If you don’t understand the request, cancel it.
- Bookmark Real Sites: Never reach apps through ads, DMs or reply links.
- Revoke Regularly: Follow our step-by-step revoke guide once a month.
- Upgrade Your Storage: Move long-term savings to a hardware wallet.
Remember: Real airdrops don’t rush you, and real apps never need you to sign something you don’t understand. When in doubt, don’t sign.
Next Step: Build your full scam radar with “Spot the Scam: 10 Red Flags That Save Your Money“.
