Blockchain Hacks Cost $956 Million in First Half of 2024, Down 60% from Last Year

The first half of 2024 saw approximately $956 million in losses from blockchain security incidents, a significant decline of 60% compared to the $2.373 billion recorded during the same period last year, according to a report from blockchain security firm SlowMist. While the total value lost decreased sharply, the number of reported incidents rose from 121 to 182, indicating a shift toward smaller-scale but more frequent attacks.

DeFi and Cross-Chain Bridges Remain Primary Targets

The decentralized finance (DeFi) sector bore the brunt of the attacks, with 116 incidents accounting for roughly $490 million in losses. Cross-chain bridge vulnerabilities also remained a major concern, with 20 incidents totaling approximately $346 million. A single exploit targeting the Kelp DAO protocol accounted for about $292 million of that figure, highlighting how concentrated losses can be in the bridge ecosystem.

By blockchain network, Ethereum suffered the highest losses at $134 million, followed by $BNB Chain at $36.35 million and Arbitrum at $4.93 million. These figures reflect the concentration of DeFi activity and liquidity on these networks, making them attractive targets for attackers.

Common Attack Vectors: Vulnerabilities and Key Theft

SlowMist’s analysis of attack methods reveals that contract and logic vulnerabilities were the most common entry point, involved in 85 incidents. The theft of private keys and credentials accounted for 17 incidents, while supply chain attacks were responsible for 12 incidents. These patterns underscore the importance of rigorous code audits, secure key management, and vendor vetting for blockchain projects.

Why This Matters for Investors and Users

The 60% year-over-year decline in total losses suggests that improved security practices, better auditing standards, and faster incident response may be having an effect. However, the increase in the number of incidents indicates that attackers are adapting, targeting smaller projects with weaker defenses. For users, this means that due diligence on protocol security remains essential, especially when interacting with newer DeFi platforms and cross-chain bridges. The concentration of losses in a few large exploits also serves as a reminder that even well-known protocols can be vulnerable.

Conclusion

The first half of 2024 data from SlowMist presents a mixed picture for blockchain security. While the total financial damage has dropped significantly, the rising frequency of attacks and the persistent vulnerability of DeFi and cross-chain bridges demand continued vigilance from developers, auditors, and users alike. The industry has made progress, but the threat landscape is evolving, and security must remain a top priority.

FAQs

Q1: What caused the 60% drop in blockchain hack losses?
A: The decline is likely due to a combination of improved security practices, more rigorous smart contract audits, faster incident response, and the absence of several multi-billion dollar exploits that inflated the 2023 figures. However, the increase in the number of incidents suggests attackers are targeting smaller, less secure projects.

Q2: Which blockchain network was most affected by hacks in H1 2024?
A: Ethereum recorded the highest losses at $134 million, followed by $BNB Chain at $36.35 million and Arbitrum at $4.93 million. These networks host the largest concentration of DeFi protocols, making them prime targets.

Q3: What is the most common type of blockchain vulnerability exploited?
A: Contract and logic vulnerabilities were the most common, involved in 85 out of 182 incidents. Private key theft (17 incidents) and supply chain attacks (12 incidents) were also significant vectors. These findings highlight the need for thorough code reviews and secure key management practices.