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

Harmony’s team said it has notified exchanges in an attempt to prevent further malicious transactions and is expected to update users soon

article-image

Zeeland Bridge, Netherlands. Credit: Unsplash

share
  • Horizon has been hacked for $100 million while stewards of the bridge said they are working with authorities to identify the attacker
  • Funds and assets from the Bitcoin bridge remain unaffected as they are stored in decentralized vaults, Harmony’s team said

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.

“We discovered the hack this morning and immediately began reaching out to our cyber security partners, exchanges, and the FBI, and we’re actively working with all three,” Harmony told Blockworks via Telegram.

“Once contact was established, our next goal was to communicate the situation with our community via Twitter and we’ve since published a Medium article which will receive ongoing updates as information is gathered,” the team added.

Harmony representatives 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 is audited by blockchain security firm Peckshield.

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.

Harmony told Blockworks its founder, Stephen Tse, will discuss the hack and the team’s ongoing efforts via YouTube on Friday, as well as an update on their attempt to identify the culprit and retrieve the stolen funds.


Get the news in your inbox. Explore Blockworks newsletters:

Tags

Decoding crypto and the markets. Daily, with Byron Gilliam.

Upcoming Events

Javits Center North | 445 11th Ave

Tues - Thurs, March 24 - 26, 2026

Blockworks’ Digital Asset Summit (DAS) will feature conversations between the builders, allocators, and legislators who will shape the trajectory of the digital asset ecosystem in the US and abroad.

recent research

Flying_Tulip.png

Research

Flying Tulip's perpetual put option provides real principal protection, but investors must pay a valuation premium today for products that have to be built over the next 24 months. This structure works best as a stablecoin substitute where the put allows continuous monitoring—accept opportunity cost in exchange for asymmetric upside if the team executes on its ambitious cross-collateral architecture.

article-image

As flows consolidate and volatility fades, finding edge now means knowing which games are still worth playing

article-image

Value distribution came to $1.9 billion distributed in Q3, though total revenues have yet to beat 2021 heights

article-image

MegaETH public sale auction ends tomorrow, and the free money machine has attracted people who like free money

article-image

With tBTC under the hood, Acre abstracts bridging and converts non-BTC rewards to bitcoin

article-image

Accountable is also eyeing mid-November for mainnet launch

article-image

“Adjusted for size, I think it may be the most successful ETP launch of all time,” Bitwise CIO Matt Hougan says