Wallet Drainers, Token Approvals and Permit Signatures: Protect Your Wallet

Not every loss comes from a bad token. Some of the biggest come from a single click: you connect your wallet to a fake site, sign something that looks harmless, and your wallet is emptied. That's a wallet drainer — a phishing kit that tricks you into giving a scammer permission to move your assets.

//How big is the problem?

Scam Sniffer, which tracks Web3 phishing, estimated that wallet drainers took about $494 million from around 332,000 addresses in 2024. Losses fell sharply in 2025 — to roughly $84 million across about 106,000 victims — but attackers shifted to smaller, more frequent thefts, and permit-style signatures stayed among the most effective techniques. Those figures cover the EVM chains Scam Sniffer monitors, so the true total is higher.

//How drainers work

Token approvals

On EVM chains, letting a DEX trade your tokens requires an approval: permission for a contract to move a specific token from your wallet. Many apps ask for unlimited approvals for convenience. If you approve a malicious contract — or a legitimate one that's later exploited — it can move that token whenever it likes, without asking again.

Permit and Permit2 signatures

Permit signatures grant the same kind of approval with an off-chain signature instead of a transaction. No gas, no obvious "approve" step — just a message to sign. Drainer sites love them because many people treat "signing a message" as harmless. It isn't.

Malicious transactions on Solana

On Solana, drainers usually ask you to sign a transaction that transfers tokens or reassigns account ownership, disguised as a claim, mint or "verification". Wallet simulations help, but only if you read them.

//Where you meet drainers

• Fake airdrop and claim pages promoted in replies, DMs and Telegram groups.
• Cloned sites of real DEXs, launchpads and token pages, often from sponsored search results.
• Fake "support" agents who ask you to "sync" or "validate" your wallet. See crypto Telegram scams.
• Compromised accounts of real projects posting a malicious link.
• Lookalike token pages for hyped launches. See fake tokens and address poisoning.

//How to protect yourself

1. 01Use a burner wallet for new launches and unknown sites. Keep long-term holdings in a separate wallet that never connects to anything experimental.
2. 02Read every signature. If you can't tell what a request does, don't sign it. "Permit", "setApprovalForAll", "increaseAllowance" and ownership changes deserve extra suspicion.
3. 03Avoid unlimited approvals when your wallet lets you set an amount.
4. 04Revoke old approvals regularly with a reputable approval checker (for example, revoke.cash or your block explorer's token approval tool).
5. 05Bookmark the sites you use. Don't trust sponsored search results or links in replies.
6. 06Never share a seed phrase — no real support team, airdrop or "wallet validation" will ever need it.
7. 07Use a hardware wallet for meaningful amounts, and confirm details on its screen.

//If you've signed something bad

Act fast. Revoke approvals to the contract involved, then move remaining assets to a fresh wallet with a new seed phrase — a compromised wallet should be treated as permanently unsafe. Be wary of "recovery experts" who contact you; they're a common second scam.

//Bottom line

Token research protects you from bad tokens. Wallet hygiene protects you from bad links. You need both — pair this guide with the rug pull red flags and the due diligence checklist.