Twenty-four million dollars left the AFX bridge in a single transaction. At 21:30 UTC on July 22, Blockaid spotted the exploit: 24,150,000 USDC moved from AFX's bridge contract to an attacker-controlled address on Arbitrum. By the time analysts finished tracing the funds, the money was already gone from the stablecoin ecosystem.

What actually happened

The target was not Arbitrum's native bridge. AFX, a decentralized perpetual trading platform built on Arbitrum, operates its own third-party cross-chain bridge for USDC deposits. That infrastructure is what the attacker hit. Arbitrum's core bridge kept running without interruption, and Offchain Labs co-founder Steven Goldfeder confirmed the suspicious transaction originated from a third-party protocol, not anything Arbitrum controls natively.

PeckShield tracked the stolen funds moving from Arbitrum to Ethereum, where the attacker converted the entire USDC haul into 12,467.5 ETH at an average price of roughly $1,937 per coin. That conversion matters: stablecoins can be frozen at the issuer level, ETH cannot. The attacker effectively made asset recovery far harder with a single swap. As of the time of reporting, no funds had been returned, and AFX had released no statement explaining how the bridge was compromised.

Bridge security back in the spotlight

This is not an isolated incident. Earlier in 2026, Stake DAO shut down its vsdCRV bridge after an unauthorized mint on Arbitrum. Kelp DAO's LayerZero bridge lost around 116,500 rsETH, worth roughly $292 million at the time. The pattern is consistent: attackers go after the application-layer bridges, not the base-layer infrastructure.

For anyone using DeFi protocols built on top of major networks, the AFX case is a reminder that the security of the underlying chain and the security of the app running on it are completely separate questions. Blockaid, Offchain Labs, and AFX are still investigating. No vector has been publicly disclosed.

This article is for informational purposes only and does not constitute financial advice or a recommendation to buy, sell, or hold any asset.