Module 3 · Safety
Wallet hygiene & scams
The signatures and approvals that quietly drain wallets.
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Token approvals & drainers
Learn
To trade a token on a DEX you grant an approval — permission for a contract to move that token on your behalf. Malicious sites trick you into approving a *drainer* contract with an unlimited allowance, then sweep the token whenever they like. The signature looks innocuous.
Approve only what you need, revoke approvals you no longer use, and read what you're signing. A 'set approval for all' on an unknown contract is how most NFT wallets get drained.
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Recall
A malicious unlimited token approval lets an attacker…