Hackers attack Bitcoin platform Alex Protocol, steal $8.3M—Protocol vows reimbursement

The Bitcoin-based DeFi platform Alex Protocol confirmed an $8.3 million exploit on June 6, marking one of the largest attacks ever on the Stacks blockchain. Hackers drained liquidity pools by exploiting a vulnerability in the protocol’s self-listing verification system, stealing millions in STX, sBTC, stablecoins, and wrapped Bitcoin.

In a public statement, the team assured users that the Alex Lab Foundation would fully reimburse losses using treasury reserves. Payments will be distributed in USDC, with a structured claims process set to begin by June 8.

How the Alex Protocol exploit unfolded

According to the statement, the attackers targeted Alex Protocol’s smart contract logic, bypassing security checks to siphon:

• 8.4 million STX tokens ($5.5M)

• 21.85 sBTC (~$1.4M)

• 149,850 USDC/USDT ($150K)

• 2.8 WBTC (~$295K)

Blockchain analysts traced the stolen funds to multiple wallets, though the perpetrators remain unidentified. The protocol has yet to release a technical post-mortem but pledged transparency in upcoming reports.

Reimbursement plan: Key details for affected users

The Alex Foundation outlined a three-step compensation process:

1. Onchain notifications (by June 8): Affected wallets will receive claim forms.

2. Submission deadline (June 10): Users must provide a valid receiving address.

3. USDC payouts (within 7 days): Calculated using attack-day exchange rates (10:00 AM–2:00 PM UTC).

Users missing notifications were urged to contact the protocol’s support team immediately.

Repeat security failures plague Alex Protocol

This marks the second major breach for Alex Protocol in 2024. In May, hackers stole $4.3 million via a cross-chain bridge exploit—an attack later linked to North Korea’s Lazarus Group.

Despite prior collaboration with investigator ZachXBT to trace stolen funds, the protocol’s recurring vulnerabilities raise questions about its audit processes. Critics argue the platform must prioritize security upgrades to restore trust.

Industry reactions and next steps

DeFi analysts warn that the protocol’s back-to-back exploits could deter institutional adoption of Bitcoin-based finance. The Stacks blockchain, which hosts the protocol, has historically avoided large-scale hacks, making this incident particularly damaging.

The foundation’s pledge to cover losses mirrors responses from platforms like Euler Finance, but long-term recovery hinges on Alex Protocol delivering robust safeguards.