Two Ethereum Bridges Drained of $31.7M in Hours as B² Network Halts Staking

Two EETH$1,858.54▼1.30% bridge protocols lost a combined $31.7 million within hours of each other on July 22, while a third project — BBTC$64,055.00▼1.40% Layer 2 network B² — suspended staking the same day, exposing what one report called “three distinct control failures” across DeFi in a single 24-hour window.

According to CryptoSlate, the first hit landed on AFX Bridge, operating on Arbitrum, where an attacker drained $24 million in UUSDC$0.9997▲0.00% through a targeted exploit. Hours later, the Verus Ethereum bridge bled another $7.5 million — pushing the combined toll to roughly $31.5 million, in line with the $31.69 million figure in the report. B² Network halted staking the same day, a separate operational and governance failure rather than a direct exploit, per CryptoSlate’s framing.

The Verus loss carries a particular sting. That $7.5 million drain came from the same bug class that attackers had already used in a May incident, according to an X post by @DjaniWhaleSkul cited in the research. Either the bridge’s operators attempted a patch that didn’t hold, or they never fully identified the root cause the first time. A repeat exploit of the same vulnerability isn’t a black-swan event. It’s a maintenance failure — and it raises an uncomfortable question about how many other bridges are running code that was patched but never actually fixed.

AFX Bridge’s $24 million USDC loss on Arbitrum dwarfs the Verus figure by nearly three to one. That scale suggests a deliberate, high-value target rather than an opportunistic probe. Bridge contracts pool assets from multiple chains, which makes them structurally attractive to anyone who understands cross-chain messaging logic. When a bridge’s validation or signature mechanism breaks, the attacker’s upside isn’t a token swap or a flash-loan arbitrage — it’s the entire pool.

B² Network’s staking halt introduces a different failure mode. B² is a Bitcoin Layer 2 protocol, and suspending staking on July 22 represents an internal decision — whether triggered by a discovered vulnerability, a liquidity crunch, or a governance dispute — not a smart-contract drain by an outside attacker. CryptoSlate’s framing of “three distinct control failures” groups both categories together, which is useful for identifying a pattern but shouldn’t obscure the mechanical difference between an exploit and a suspension. The ChainLight blog on Bitcoin L2 solutions provides broader context on the operational challenges facing Bitcoin Layer 2 networks like B² as they attempt to replicate Ethereum’s DeFi stack.

The timing is the real story. Three control failures across three protocols in one day doesn’t prove coordination. But it does challenge the assumption that bridge risk is purely idiosyncratic. One bridge getting exploited is a bug. Two bridges and a staking protocol failing within hours is a sector-level stress signal. Bridge infrastructure has long been the softest target in cross-chain DeFi, and the pattern isn’t new — research cites a prior $31.7 million hack on the Alex protocol in the Stacks ecosystem in August 2024, a near-identical dollar figure that shows how consistently these losses recur across chains and over time.

Market conditions offered no cushion. Ethereum was trading at $1,859, down 0.59% on the day, with ETH dominance at 9.9% of a total crypto market cap of $2,272.39 billion. The Fear & Greed Index sat at 27 — firmly in Fear territory. Bitcoin held at $64,060, off 0.92%, with BTC dominance at 56.5%. None of those moves were catastrophic in isolation, but they sketched a market already leaning risk-off before the bridge incidents piled on.

For DeFi users, the central question is whether bridge operators can close the gap between deploying a patch and actually resolving a vulnerability. The Verus repeat exploit is the sharpest warning in this cluster: a known bug class that was supposedly addressed in May came back in July and cost another $7.5 million. Until bridges can demonstrate that fixes are complete — not just deployed — cross-chain infrastructure will remain the sector’s most reliable attack surface.

The next concrete markers: whether AFX Bridge or Verus publishes a post-mortem with a genuine root-cause analysis, and whether B² Network resumes staking with a public explanation for the suspension.