In brief

  • Hackers targeted a smart contract vulnerability in an upcoming project by Yearn founder Andre Cronje.
  • They managed to steal over $15 million; but returned $8 million to a wallet owned by Cronje.
  • The "test in prod" approach proved costly, as Cronje alleged received threats after the hack.

Experimental DeFi platform Yearn Finance cultists were hit with losses this morning after an unidentified hacker exploited a smart contract vulnerability in Eminence, an upcoming gaming project built by Yearn founder Andre Cronje.

The exploit allowed them to mint unlimited new tokens and steal over $15 million in the process. And yet, strangely, they would later return half the stolen crypto.

Known for his “I test in prod” approach—a meme reference to testing in production on the Ethereum mainnet instead of the testnet (as developers usually do)—Cronje teased the project’s logo last night over Twitter.

What followed later was a hallmark crypto move: The lack of information around the project did not stop speculators from rushing in; they purchased over $15 million worth of Eminence’s EMN tokens in under three hours, given its association to Cronje and his reputation as a trusted builder in the crypto space.

But then someone who actually read Eminence’s contracts discovered a flaw—a rogue function that would allow the hacker to mint unlimited EMN tokens, burn an equal amount of EMN tokens against another cryptocurrency, and sell that to those rushing in to buy EMN.

Needless to say, the hacker went ahead with the plan.

But what happened after that wasn’t a hallmark of crypto. The hacker then returned over $8 million of the stolen funds to Cronje’s own deployer contracts, which the developer promptly said would be returned to all those who rushed into buying EMN.

It didn't, however, stop the threats that Cronje allegedly received for the losses suffered by the speculators.

“As I am receiving a fair amount of threats, I have asked to yearn treasury to assist with refunding the 8m the hacker sent. The multisig is safer and as such, I feel more comfortable with them having the funds. Funds will be returned to holders pre-hack snapshot,” said Cronje.

At press time, Cronje said he would continue to develop Eminence in the coming weeks; with a disclaimer this time, “Let me be clear, do not use random contracts I deploy unless I reference it in a Medium article.”

Or maybe just don’t test in prod?