Hacker who breached Sentiment returns $870,000 to the protocol

The hacker who breached the Sentiment DeFi liquidity protocol has returned 90% of the stolen funds.

After successful negotiations with the exploiter, 90% of hacked funds have been returned as agreed. A full statement will follow in the coming hours.

— Sentiment (@sentimentxyz) April 6, 2023

The protocol team sent the hacker a message offering a $95,000 reward on condition that the assets were returned by April 6. Otherwise, Sentiment would offer a similar reward for any information about the offender.

The developer behind MetaMask, Taylor Monahan, tracked the sequence of transactions — in total the hacker sent to the platform 465.75 ETH (~$870,000 at the time of writing), leaving 51.75 ETH as the reward.

Oh wow, there it is. Final 51.75 ETH returned and he’s off into the sunset (or something) ?https://t.co/GBB7SclM2P pic.twitter.com/8iTytoAqqP

— Tay ? ? (@tayvano_) April 6, 2023

On April 5, the attacker took advantage of a re-entry vulnerability on the Balancer platform to execute malicious code. He took a flash loan on Sentiment, manipulating data to overstate the collateral value and withdrew via the Synapse Bridge 536,738.4 USDC on the Arbitrum network Arbitrum.

Later Beosin experts confirmed this, noting that the protocol’s losses from the attack amounted to about $1 million.

According to DeFi Llama, in the wake of the hack the value of assets blocked in Sentiment fell from $10.78 million to $5.27 million. At the time of writing, the figure stood at $3.28 million.

Back in early April, the attacker returned almost all of the stolen funds. In total, the hacker withdrew cryptocurrency worth $196 million from the platform.