Frontend Security Insights from the Largest Hacker Incident in Web3 History

On February 21, 2025, a well-known trading platform experienced a major security incident, with approximately $1.46 billion in crypto assets being transferred to an unknown address. This incident not only shocked the entire crypto industry but also sparked deep reflections on Web3 security.

Event Review

The attacker successfully induced the signers of the multi-signature wallet to approve a malicious transaction through a carefully designed phishing attack. The specific steps are as follows:

1. The attacker pre-deploys a malicious contract containing a backdoor for fund transfer.
2. Tamper with the Safe front-end interface so that the transaction information seen by the signer is inconsistent with the data actually sent to the hardware wallet.
3. Obtain valid signatures through a forged interface, replace the implementation contract of the Safe multi-signature wallet, thereby controlling the cold wallet and transferring assets.

Investigation Findings

After the forensic investigation conducted by professional institutions, the preliminary results indicate:

• Discovered resources injected with malicious JavaScript code in Safe's cloud storage.
• Malicious code is designed to manipulate transactions and alter transaction content during the signing process.
• The source of the attack appears to be from Safe's cloud infrastructure.
• No signs have been found indicating that the trading platform's own infrastructure has been compromised.

Security Risk Analysis

1. Front-end security vulnerabilities: The Safe front end lacks basic resource integrity ( SRI ) verification, allowing tampered JavaScript code to be executed.

2. Limitations of Hardware Wallets: When handling complex transactions, hardware wallets are unable to fully parse and display detailed transaction data for multi-signature wallets, resulting in the risk of "blind signing".

3. User trust issue: Signers place excessive trust in the front-end interface and confirm transactions without fully verifying the transaction content.

The Integration of Frontend Security and Web3

With the development of Web3 technology, the boundaries between front-end security and blockchain security are becoming increasingly blurred. Traditional front-end vulnerabilities may have more severe consequences in a Web3 environment, while vulnerabilities in smart contracts and issues with private key management further increase the risk.

Scenario 1: Transaction Parameter Tampering

Question: The interface shows transfer, but actually executes authorization.

Solution: Use EIP-712 structured signature verification

1. Front-end generated verifiable data
2. Smart Contract Verification Signature

Effect: Any tampering of front-end parameters will cause the signature to mismatch, and the transaction will automatically roll back.

Scenario 2: Blind Signature Hijacking

Question: The hardware wallet parsing rules have been tampered with, resulting in a mismatch between the displayed content and the actual execution.

Solution:

1. Upgrade hardware wallet firmware to support EIP-712
2. Implement on-chain mandatory semantic matching

Security Recommendations

1. Implement a multi-layered security verification mechanism, including device security, transaction verification, and risk control mechanisms.

2. Front-end development requires comprehensive validation of aspects such as DApp access, wallet connection, message signing, transaction signing, and post-transaction processing.

3. Use smart contract security audit tools, such as formal verification and AI-assisted security specification generation.

4. Establish a real-time monitoring system to promptly detect and respond to potential security threats.

5. Raise user security awareness and cultivate good habits for transaction verification.

Conclusion

The Bybit incident revealed deep-seated issues in security management and technical architecture within the cryptocurrency industry. In the face of continuously evolving attack techniques, the industry needs to enhance its protective capabilities comprehensively from multiple levels. Frontend developers should strive to create a safer and more trustworthy user interaction experience, shifting from "passive patching" to "active immunity." Only in this way can we truly safeguard the value and trust of every transaction in the open world of Web3.