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

Research Report Templates (19).png

Research

Built on Solana, Loopscale is an orderbook-based lending protocol that pairs the efficiency of direct market matching with the flexibility and UX of modular protocols. We believe Loopscale can help scale NNAs in Solana DeFi and act as their foundational credit layer. Stablecoin deposits and select USD-pegged Loops on Loopscale are offering competitive yields, with an additional upside from farming the protocol and adjacent ecosystem projects (e.g., OnRe, Hylo) for potential future airdrops.

article-image

A recent mistrial illustrates how juries need more background information when it comes to judging complex systems like Ethereum

article-image

The Senate advanced a bipartisan funding package aimed at ending the shutdown, and bitcoin rose from its $100K bottom

article-image

The team is betting that a 20-minute hardware trust window beats a new alt-L1

article-image

To learn how to navigate the physical world, robots need visual data

article-image

Risks and illiquidity come to surface in the wake of a red October

article-image

Advice from Neal Stephenson, Kyle Broflovski, and Crypto Mom on building in crypto