SUPERCYCLE Honeypot
What happened
SUPERCYCLE ($SUPER) is a BEP-20 token whose transfer and transferFrom both refuse any recipient equal to a variable called newun. The newun variable is filled either by the owner through transfernewun or automatically, with the recipient of the first transferFrom made while it is unset. Tokens can still leave the newun address but cannot be sent back to it.
De.Fi's REKT database lists the token as an exit scam/honeypot and states that the contract owner could disable the transfer function, which restricted users in selling their tokens. The code shows the block is possible; no opened source shows what newun was set to or what happened to holders.
How it happened
- The constructor sends the whole supply to the deployer:
balances[owner] = _totalSupply;. The deployer is alsoownerand the only caller of the owner-only functions. transfernewun(address _newun) public onlyOwnersetsnewun, andtransferstarts withrequire(to != newun, "please wait");, so no direct transfer can send tokens to that address.transferFrombeginsif(from != address(0) && newun == address(0)) newun = to; else require(to != newun, "please wait");. The firsttransferFromwith a non-zerofromwhilenewunis unset succeeds and stores its recipient asnewun. Every latertransferFromto that recipient reverts beforebalances[from]is reduced, so the sender keeps their tokens.- Nothing checks
fromagainstnewun, so transfers out of that address are not blocked by this code. Which addressnewunends up as depends on the firsttransferFromor on the owner; the code does not name it. - The block can be lifted only by the owner pointing
newunat an address nobody sends to. Setting it back to the zero address re-arms the automatic capture, because the nexttransferFromwrites a new recipient into it.Ownedalso allowstransferOwnership/acceptOwnership, and nothing in the file renounces ownership. - The opened write-up (dated 2021-04-11) describes this same code in other BNB Smart Chain tokens, where
newunwas the PancakeSwap pool set on the first add-liquidity call, so buys worked and sells back to the pool reverted. It does not cover SUPERCYCLE, and no transaction for this token was opened; the listing for this record comes from De.Fi's REKT database.
Protocol details
Evidence
- report @Token_Sniffer incident report twitter.com
- report SUPERCYCLE source on Sourcify (exact match) repo.sourcify.dev
- report Token Sniffer tweet cited by De.Fi as proof (not retrievable) twitter.com
- address SUPERCYCLE verified source on BscScan bscscan.com
- analysis BSC-SCAM: Stealthy Liquidity Pool Block on PancakeSwap cryptot3ddybear.gitlab.io
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