April DeFi hacker theft exceeds $600 million: Lazarus Group is suspected to be the mastermind

In April 2026, the decentralized finance (DeFi) sector faced its most severe security challenge in recent years. According to on-chain security agencies, the total theft amount caused by hacker attacks that month exceeded $606 million, setting a new monthly loss record. Multiple mainstream protocols were breached one after another, and the North Korea-linked hacker organization Lazarus Group was identified by several investigative agencies as the main behind-the-scenes culprit of the series of attacks. These events not only exposed the fragility of DeFi infrastructure but also prompted the industry to reevaluate the risk boundaries of cross-chain interactions and private key management.

How to Confirm the Actual Loss Scale of Major Security Incidents in April

As of April 27, 2026, publicly disclosed DeFi hacker attack incidents have resulted in over $606 million in assets stolen. The three largest cases are: KelpDAO with approximately $292 million lost, Drift Protocol with about $285 million lost, and Purrlend with roughly $1.5 million lost. Additionally, protocols like Scallop reported losses ranging from hundreds of thousands to millions of dollars. These figures come from post-incident disclosures by the projects and fund tracking reports from on-chain monitoring platforms, excluding unpublicized or unconfirmed small-scale attacks. Dividing April’s losses by week shows that losses increased week by week in the first three weeks, while in the fourth week, due to some projects suspending services or upgrading contracts, losses slightly declined.

What Cross-Protocol Attack Methods Did the Attackers Use?

Technical reviews of the disclosed incidents reveal that attackers mainly exploited contract permission management vulnerabilities and flaws in cross-chain bridge logic. In the KelpDAO incident, attackers gained control of a management wallet’s private key, bypassed multi-signature verification, and directly called the withdrawal function in the contract to transfer staked assets in batches. The Drift Protocol attack was more complex: attackers used malicious contracts deployed on another chain to forge deposit proofs via cross-chain messaging protocols, allowing them to over-borrow assets on the target chain. These methods indicate that attackers are no longer limited to single-contract vulnerabilities but are leveraging trust assumptions across multiple protocols as entry points.

Why Is Lazarus Group Considered the Main Suspect?

Multiple blockchain security firms, through analysis of on-chain fund flows, linked several major attacks in April to Lazarus Group. This organization has a history of transferring illicit gains via cryptocurrency, with on-chain behavior fingerprints including: rapidly moving funds through decentralized cross-chain bridges to different networks after attacks, using mixers (such as forks or alternative protocols of Tornado Cash) to wash funds in batches, and ultimately directing some funds to addresses associated with fiat on-ramps. In April’s incidents, the subsequent transfer paths of stolen funds from KelpDAO and Drift closely resemble patterns seen in past cases (such as Ronin Bridge and Harmony Bridge attacks). Although no organization or individual has publicly claimed responsibility, the behavioral similarities make Lazarus Group the most plausible suspect at present.

How Are Stolen Funds Transferred Cross-Chain and Mixed?

After gaining access, attackers prioritize the efficiency and concealment of fund transfers. For the two largest incidents in April, attackers moved most assets from the original chains (like Ethereum and Solana) to multiple emerging Layer 2 networks or more privacy-focused blockchains within hours via cross-chain bridges. Subsequently, the funds were split into hundreds of small transactions, flowing into various decentralized mixing protocols. These mixers use zero-knowledge proofs or multi-party computation techniques to hide the link between input and output addresses, making it difficult for conventional on-chain tracking tools to identify the real recipients. Some funds, after mixing, were further converted into other types of crypto assets via synthetic asset platforms, increasing the difficulty of freezing and recovery.

How Did the Chain of Attacks Impact the Total Locked Value (TVL) in DeFi?

The massive security incidents had a direct impact on market confidence, reflected in the total value locked (TVL) in the DeFi ecosystem. According to on-chain data, within 72 hours after the attacks, the TVL of the affected major protocols dropped on average by 35% to 60%. For example, KelpDAO’s TVL plummeted from about $850 million before the attack to below $310 million. The broader DeFi market also experienced a chain reaction: users tended to withdraw assets from projects with complex cross-chain interactions and open contract permissions, shifting toward more mature lending protocols or centralized custody solutions. As of April 27, Ethereum’s overall DeFi TVL had decreased by about 12% from the beginning of the month, while some protocols focusing on risk isolation saw slight net fund inflows.

Can Aave’s Recovery Fund Become an Industry Safety Standard?

In response to the ongoing security losses, leading lending protocol Aave announced in mid-April the establishment of a recovery fund aimed at partially compensating users affected by protocol issues not related to code vulnerabilities (such as external dependency attacks or governance exploits). The fund operates with contributions from the Aave treasury and some ecosystem partners, with an independent risk assessment committee reviewing each incident’s eligibility for compensation. Although the fund has not yet covered all security incidents in April, its establishment has sparked industry discussions—should a “DeFi safety reserve” similar to bank deposit insurance be created? Supporters believe this could boost user confidence, while opponents argue that such a model might introduce moral hazard, encouraging projects to lower their security standards due to external bailout expectations.

How Can Individual Users Identify and Mitigate DeFi Protocol Risks?

While improving protocol security still requires time, individual users can take measures to reduce asset exposure risks. First, prioritize protocols that have undergone multiple independent security audits and have open-source code, paying attention to whether the auditors are reputable institutions. Second, carefully manage token permissions, regularly revoking unused authorizations via blockchain explorers or authorization management tools. Third, store major assets in multi-signature wallets or hardware wallets, isolating them from hot wallets used for large transactions. Fourth, monitor real-time alerts from security monitoring platforms, and immediately revoke permissions if an attack is detected. Fifth, for new protocols offering high-yield liquidity mining rewards, assume their security has not been fully verified and control the proportion of funds invested relative to total assets.

Summary

In April 2026, the DeFi ecosystem suffered over $606 million in losses due to a series of hacker attacks, with major protocols like KelpDAO and Drift Protocol falling one after another. On-chain behavior analysis strongly suggests Lazarus Group as the orchestrator behind these incidents, with highly skilled cross-chain transfer and mixing techniques. This security crisis not only caused significant TVL declines in affected projects but also prompted the industry to rethink permission management, cross-chain trust models, and user compensation mechanisms. For ordinary participants, before a unified security standard is established, actively controlling authorization scopes, isolating asset types, and staying alert to warning signals remain the most effective ways to protect their funds.

FAQ

Q: How can I quickly check if a DeFi protocol has experienced a major security incident?

A: Use security monitoring platforms (such as MistTrack by SlowMist, PeckShield Alert) or on-chain data analysis sites (like DeFi Llama’s Rug Pull tracker) to review the protocol’s historical security records. Also, follow the project’s official Discord or Twitter announcement channels; usually, after an attack, the project team will release a preliminary statement within an hour.

Q: Can assets stolen by Lazarus Group be recovered eventually?

A: Recovery is extremely difficult. The organization typically launders funds through multi-layer cross-chain bridges and mixers, with some funds eventually converted into fiat in jurisdictions with weak regulatory cooperation. Historically, only a few cases (such as law enforcement freezing some addresses before full mixing) have resulted in partial recovery.

Q: If the protocol I used was hacked in April, what should I do?

A: First, immediately revoke all contract permissions related to that protocol. Second, save your on-chain transaction hashes, authorization records, and balance screenshots. Third, follow the project’s official announcements for compensation or governance proposals; most projects will snapshot and confirm affected users before initiating voting. Do not pay any third parties claiming they can recover your funds.