Harmony’s Cross-Chain Horizon Bridge Hacked for $100M

Horizon Bridge, a cross-chain interoperability platform between Ethereum, Binance Smart Chain (BSC) and Harmony blockchain networks, has been hacked for $100 million.

The Harmony team, stewards of the bridge, said Thursday it has been made aware of the theft and has begun working with national authorities as well as forensic specialists to identify the attacker in an attempt to retrieve the stolen funds.

The team also said the hack did not impact the trustless Bitcoin bridge as funds and assets are stored on decentralized vaults and are considered “safe at this time.”

Horizon Bridge claims to be fully audited by blockchain security firm Peckshield. Blockworks attempted to contact Harmony but is yet to receive a response.

It’s the latest in a string of hacks against protocols, bridges and projects including a $20 million theft from Ethereum scaling solution Optimism earlier this month and a $320 million hack against Solana bridge Wormhole in February. Ethereum-linked sidechain Ronin Network – used for blockchain game Axie Infinity – also suffered a hack in April with a whopping $620 million stolen.

Horizon enables cross-chain transfers of digital assets between Ethereum and Harmony, as well as BSC, via a set of smart contracts deployed across those three chains. Users holding assets including stablecoins, ERC-20 tokens or Binance’s BEP-20 tokens can exchange them for corresponding assets on Harmony for a 1:1 ratio.

In a later tweet update on Thursday, Harmony’s team said it had identified the hacker’s wallet address. The address has a balance of roughly 85,837 ether or around $98 million at time of writing.

“We have also notified exchanges and stopped the Horizon bridge to prevent further transactions. The team is all hands on deck as investigations continue,” the team said.

Further updates are expected in the coming hours. This is a developing story and will be updated accordingly.

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