Funds From $100M Horizon Bridge Exploit Sent to Tornado Cash Mixing Service

A desire to work with the hacker still remains though the investigation into the theft continues until the matter is resolved, Harmony said

article-image

Blockworks exclusive art by axel rangel

share

key takeaways

  • Thieves appear to be trying to launder funds with move of $35 million stolen from the cross-chain bridge
  • Stewards of the bridge, Harmony, offered a $1 million bounty in exchange for returning the stolen funds but has so far received no response

Around a third of the $100 million stolen last week from Horizon Bridge — a cross-chain interoperability platform between Ethereum, Binance Smart Chain (BSC) and Harmony blockchain networks — has been transferred to an address belonging to crypto mixing service Tornado Cash.

Blockchain security company Peckshield did not immediately respond to attempts by Blockworks to confirm details of the transfer. Last week’s hack saw more than $98 million in various tokens siphoned off the Horizon Bridge platform and subsequently swapped to ether.

Steward of the bridge, Harmony, said in an updated blog post Sunday it was aware the hacker had begun moving funds through Tornado Cash and is reviewing various options for users and partners.

“Transparency is important in blockchain and we aim to be transparent with our community but we ask the community to remain patient during this investigation and confidentiality at this time,” Harmony said in its post.

Mixers or tumblers, such as Tornado Cash, are services providing users the ability to conceal the transaction history of certain cryptocurrencies by pooling and mixing them together with other users’ funds.

The team at Harmony offered a $1 million bounty for the return of the funds on Friday and advocated for no criminal charges to be filed, though the call remains unanswered.

“The desire to work with the hacker remains but we will continue the full investigation until resolution or the funds are returned,” Harmony said Monday.

In the post, which has been updated regularly since the hack took place last week, Harmony said its incident response team found no evidence of any breaches in its smart contract codes nor to the Horizon platform.


Get the news in your inbox. Explore Blockworks newsletters:

Tags

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

Upcoming Events

Old Billingsgate

Mon - Wed, October 13 - 15, 2025

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.png

Research

Pipe Network is a decentralized content delivery network (dCDN) that replaces the sparse, capital intensive data center footprint of traditional CDNs with a permissionless mesh of independent node operators. By orchestrating under-utilized resources that already exist at the edge, rather than purchasing or leasing thousands of servers, Pipe slashes capital intensity while letting supply expand autonomously in the places where bandwidth is scarcest and most expensive.

article-image

ETH’s “breakout marks a significant structural shift and clears the path towards…$4,000,” Kraken’s OTC desk noted

article-image

Fiscal dominance isn’t about interest rates and it isn’t about Trump, either

article-image

Firestarter Storage brings decentralized storage and delivery to Solana

article-image

After lengthy closing arguments on Wednesday, the case is now in the hands of 12 jurors

article-image

Analysts cite weak trading volume and regulatory progress as factors

article-image

Builders weigh in on Ethereum’s first decade and the decisions that will define its next one