North Korea's Cryptocurrency Theft Tactics are Evolving, with DeFi Being a Prime Target

Less than three weeks after hackers linked to North Korea used social engineering to breach the crypto trading firm Drift, another major exploit was carried out against Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests that North Korea-linked hackers are evolving their tactics, no longer just seeking vulnerabilities or stolen credentials, but instead exploiting the fundamental assumptions underlying decentralized systems. The combined impact of these two incidents points to a more organized effort by North Korea to hijack funds from the crypto sector, with over $500 million stolen in just over two weeks. 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.' 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 actually occurred. As David Schwed, COO of blockchain security firm SVRN, noted, 'The security failure is simple: a signed lie is still a lie. Signatures guarantee authorship; they do not guarantee truth.' This exploit highlights the issue of configuration choices, with Kelp 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. The fallout from the Kelp exploit has not been limited to Kelp itself, as its assets are used across multiple platforms, causing problems to spread. As Schwed explained, 'These assets are a chain of IOUs, and the chain is only as strong as the controls on each link.' When one link breaks, others are affected, leading to a wider stress event, with lending platforms like Aave that accepted the impacted assets as collateral now dealing with losses. This incident also exposes a gap between the marketing of decentralization and its actual implementation. As Urbelis put 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 the subsequent fallout demonstrate that even systems that appear decentralized can have weak points, particularly in less visible layers like data providers or infrastructure. This shift in focus towards these layers may explain why Lazarus, a group linked to North Korea, has begun targeting cross-chain and restaking infrastructure. These layers are critical but complex, often sitting underneath more visible applications, and tend to hold large amounts of value, making them attractive targets. As Lazarus continues to adapt, the biggest risk may not be unknown vulnerabilities but known ones that are not fully addressed. The Kelp exploit did not introduce a new kind of weakness but showed how exposed the ecosystem remains to familiar ones, especially when security is treated as a recommendation rather than a requirement.