In June 2022, Harmony’s Horizon Bridge lost about $100 million in virtual currency after attackers compromised bridge-validator private keys and moved assets including USDC, ETH, USDT, BNB, and other tokens through wallet hopping and Tornado Cash. Harmony described the event as a coordinated attack on internal infrastructure rather than a smart-contract exploit, and the FBI later attributed the theft to Lazarus Group/APT38.