AFX Protocol Bridge Hacked: $24.15 Million in USDC Stolen

A cross-chain bridge managed by the Arbitrum-based protocol AFX has fallen victim to a large-scale exploit. Onchain security firm Blockaid detected the attack on 22 July at 21:30 UTC. In total, around $24.15 million in USDC, the dollar-pegged stablecoin from Circle, is involved.

What exactly happened

According to Blockaid, the attacker targeted the AFX bridge, siphoning off 24,150,000 USDC worth over $24.1 million in a single transaction. The transaction can be found on Arbiscan and shows how the tokens flowed from the bridge contract to an external address.

It is important to note that this is expressly not the official Arbitrum bridge. The compromised bridge is independently managed by AFX and stands apart from the broader Arbitrum network. Unfortunately, exploits on protocol-owned bridges remain a recurring problem in the crypto world. Earlier, for example, we saw how an oracle exploit led to a crash of over 99% for another stablecoin.

Cross-chain bridges remain a weak link

Cross-chain bridges have long been known as one of the most vulnerable parts of the DeFi ecosystem. Large amounts of tokens are locked up in such contracts, making them an attractive target for attackers. A small security flaw in the code can therefore lead to huge losses in a short period of time, as this incident once again shows.

More details on exactly how the attacker managed to gain access to the funds have not been disclosed at the time of writing. Blockaid indicates it detected the attack, but further technical analysis is still ongoing. More news on hacks and attacks in the crypto market will follow as soon as more information becomes available.