A hidden blacklist function can block your wallet from selling — turning a legitimate-looking token into a permanent trap.
A blacklist trap is a sophisticated honeypot variant where the smart contract contains a function that allows the owner to block specific wallet addresses from selling. Unlike obvious honeypots that block everyone, blacklist traps can selectively target individual buyers — making them much harder to detect.
A blacklist is a mapping in a smart contract that stores wallet addresses that are prohibited from performing certain actions — typically selling. When a sell transaction is executed, the contract checks if the sender’s address is in the blacklist. If it is, the transaction reverts.
Legitimate projects use blacklists for bot prevention during launch. Scammers use them to selectively trap buyers after they purchase.
The attack pattern is consistent across most blacklist scams:
Blacklist traps are particularly dangerous because tokens can trade normally for days or weeks before the trap is triggered. Many buyers feel safe after early successful trades.
Standard simulation tools check if selling is possible from a test wallet. They will not catch blacklist traps unless they specifically check for the existence of blacklist functions in the contract code.
Not every blacklist function is a scam. Understanding the difference matters:
The key signal is whether ownership has been renounced. If the owner can still call the blacklist function, the risk is active regardless of stated intentions.
DexScanr analyzes contract source code to detect blacklist functions, ownership status, and whether they pose active risk.
DexScanr goes beyond basic sell simulation by analyzing the contract code itself for blacklist patterns. The scanner checks:
A token with a blacklist function that has renounced ownership is safe — the function exists in the code but nobody can call it. DexScanr distinguishes between active and inactive blacklist risk.