https://techcrunch.com/2022/06/24/harmony-blockchain-crypto-hack/

A hacker has exploited a vulnerability to steal $100 million from Harmony’s Horizon Bridge, which allows users to transfer their crypto assets from one blockchain to another.

Harmony, the U.S. crypto startup behind Horizon, said in a blog post on Friday that it was notified of a “malicious attack” on its proprietary Horizon blockchain bridge on Thursday. Blockchain bridges, also known as cross-chain bridges, facilitate communication between different blockchains and allow users to send assets from one chain to the other. Using Harmony’s Horizon bridge, for example, users can move assets — including tokens, stablecoins, and NFTs — between Ethereum, Binance Smart Chain, and Harmony blockchains.