CoinMarketCap data shows the value of Harmony's native token, ONE, has plunged 12% in 24 hours — meaning this altcoin has now fallen out of the top 100 cryptocurrencies by market cap.
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Approximately $100 million has been stolen after the Horizon bridge was hacked.
The platform enables investors to swap cryptocurrencies between blockchains.
Harmony Protocol, which runs the Horizon bridge, confirmed the hack on Twitter in the early hours of Friday morning, saying:
"We have begun working with national authorities and forensic specialists to identify the culprit and retrieve the stolen funds."
A crypto address shared by the project currently has a balance of 85,867 ETH.
Harmony stressed that its trustless Bitcoin bridge was not affected as a result of the incident — adding: "Its funds and assets stored on decentralized vaults are safe at this time."
The statement continued:
"We have also notified exchanges and stopped the Horizon bridge to prevent further transactions. The team is all hands on deck as investigations continue."
Were Warnings Ignored?
Some in the crypto community have been raising concerns about the Horizon bridge for months.
Back in April, @_apedev claimed the bridge's security was based on a multisig wallet that has just four owners, writing:
"So all in all, if two of the four multisig signers are compromised, we're going to see another nine-figure hack."
This isn't even the first time that a bridge has fallen victim to an exploit because of this.
Ronin Network suffered the biggest crypto hack on record back in March. Before the attack, that blockchain consisted of nine validator nodes — and signatures from five of them were needed to initiate a deposit or a withdrawal. Hackers suspected to be from North Korea managed to gain control through social engineering attacks.
CoinMarketCap data shows that the value of Harmony's native token, ONE, has plunged by 12% in the past 24 hours — meaning this altcoin has now fallen out of the top 100 cryptocurrencies by market cap.