North Korea's Cryptocurrency Theft Strategies Are Evolving, with DeFi Being Repeatedly Targeted

Less than three weeks after hackers with ties to North Korea used social engineering to breach the cryptocurrency trading firm Drift, another significant exploit has been attributed to the nation, this time targeting Kelp, a restaking protocol integrated into LayerZero's cross-chain infrastructure. This attack signals an evolution in the tactics employed by North Korea-linked hackers, who are no longer just seeking vulnerabilities or stolen credentials but are instead exploiting the fundamental assumptions underlying decentralized systems. The combined incidents of Drift and Kelp suggest a more organized effort by North Korea to siphon funds from the cryptocurrency sector, rather than isolated breaches. According to Alexander Urbelis, Chief Information Security Officer and General Counsel at ENS Labs, 'This is not a series of incidents; it is a cadence. You cannot patch your way out of a procurement schedule.' More than $500 million was siphoned across the Drift and Kelp exploits in just over two weeks. The Kelp breach did not involve breaking encryption or cracking keys; instead, attackers manipulated the data feeding into the system, forcing it to rely on compromised inputs and approve transactions that never occurred. The security failure is attributed to the system's design, where it checked the authorship of messages but not their truthfulness. David Schwed, COO of blockchain security firm SVRN, noted, 'This attack wasn’t about breaking cryptography; it was about exploiting how the system was set up.' A key issue was the configuration choice of relying on a single verifier to approve cross-chain messages, which, although faster and simpler to set up, removes a critical safety layer. In response, LayerZero has recommended using multiple independent verifiers to approve transactions, akin to requiring multiple signatures on a bank transfer. However, some have pushed back on this recommendation, stating that LayerZero’s default setup was to have a single verifier. The fallout from the Kelp exploit has extended beyond the platform, as its assets are used across multiple DeFi systems, leading to a wider stress event. Lending platforms like Aave, which accepted the impacted assets as collateral, are now dealing with losses. The incident also highlights the gap between the marketing of decentralization and its actual implementation. As Urbelis puts it, 'Decentralization is not a property a system has. It is a series of choices. And the stack is only as strong as its most centralized layer.' The attack on Kelp and similar infrastructure suggests a shift in focus by attackers like Lazarus towards the less visible but critical layers of the crypto ecosystem, such as cross-chain and restaking infrastructure, which are complex, hold large amounts of value, and are increasingly becoming targets. This shift may indicate that the biggest risk to the crypto sector is not unknown vulnerabilities but known ones that are not fully addressed, with the Kelp exploit demonstrating how exposed the ecosystem remains to familiar weaknesses, especially when security is treated as a recommendation rather than a requirement.