Approval management platform Revoke has issued a fix aimed at mitigating a new crypto scam, which involves baiting crypto users into revoking “fake approvals” and then stinging them with excessively high transaction fees.
On July 9, Revoke.cash stated that it had received reports of people seeing unknown approval transactions in their transaction history.
Yesterday, we received reports of people seeing unknown approval transactions in their transaction history.
— Revoke.cash (@RevokeCash) July 9, 2023
It turns out that this is a new scam where scammers use so-called gas tokens to steal money when victims revoke these "fake approvals". pic.twitter.com/vpY2sGIv0T
In reality, scammers have been using what are known as “gas tokens” to trick victims into believing they have suspicious transaction approvals.
“It turns out that this is a new scam where scammers use so-called gas tokens to steal money when victims revoke these "fake approvals".”
Gas tokens were developed when Ethereum network fees started climbing. Users could effectively store cheap gas during periods of low network demand.
“This allowed users to mint gas tokens when fees were low, and burn them when fees were high, effectively "locking in" the lower fee,” explained Revoke.
However, Revoke said that scammers have been creating fake gas tokens that they airdrop with fake approvals that users think they need to revoke.
The spurious tokens have been programmed to generate a lot of gas during the revoked transaction with the newly minted gas tokens being sent back to the scammers leaving the victim with a high transaction fee.
Revoke said it has now addressed the issue by adding a check that disables revoking approvals if there's an excessive gas fee. It advised users to ignore the fake approvals:
“Best thing to do with these fake approvals / fake tokens is to ignore them. As long as you don't interact with them, they can't steal your funds.”
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Revoke is a preventative tool that helps users practice safer crypto wallet behavior by managing or revoking active approvals such as those no longer required by DeFi protocols.
Platforms such as Revoke have been urging users to revoke approvals for Multichain following the multi-million dollar network exploit on July 7. This has given scammers a new avenue to lure victims to approve their fake transaction revokes.