North Korea's Cryptocurrency Theft Tactics Are Evolving, with DeFi Being Frequently Targeted

Less than three weeks after hackers linked to North Korea used social engineering to breach the crypto trading firm Drift, another significant exploit has been attributed to them, this time targeting Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack indicates an evolution in the tactics of North Korea-linked hackers, who are now exploiting fundamental assumptions built into decentralized systems, rather than just seeking out bugs or stolen credentials. The combined impact of these two incidents suggests a more organized effort by North Korea to hijack funds from the cryptocurrency sector. 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 total amount stolen across the Drift and Kelp exploits exceeds $500 million, accumulated over just two weeks. The Kelp breach did not involve breaking encryption or cracking keys but rather manipulating data inputs to force the system to approve transactions that did not occur. As explained by Urbelis, 'The security failure is simple: a signed lie is still a lie. Signatures guarantee authorship; they do not guarantee truth.' This exploit highlights a basic flaw in how the system was set up, relying on a single verifier to approve cross-chain messages, which, while faster and simpler, 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 argue that LayerZero's default setup was to use a single verifier, emphasizing the need for more robust security configurations. David Schwed, COO of blockchain security firm SVRN, notes, 'If you've identified a configuration as unsafe, don't ship it as an option. Security that depends on everyone reading the docs and getting it right is not realistic.' The impact of the exploit has not been limited to Kelp, as assets used across multiple platforms can spread problems. 'These assets are a chain of IOUs,' Schwed said, 'And the chain is only as strong as the controls on each link.' When one link breaks, others are affected, turning a single exploit into a wider stress event, such as lending platforms like Aave facing losses from accepting impacted assets as collateral. The attack also reveals a gap between the marketing of decentralization and its actual implementation. 'A single verifier is not decentralized,' Schwed pointed out. 'It's a centralized decentralized verifier.' Urbelis further clarifies, '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.' This means even seemingly decentralized systems can have weak points, particularly in less visible layers like data providers or infrastructure, which are increasingly the focus of attackers. The recent targeting by the Lazarus group of cross-chain and restaking infrastructure, which are critical but complex and often under visible applications, suggests a shift towards targeting the 'plumbing' of the crypto industry. These layers are not only harder to monitor but also easier to misconfigure and hold large amounts of value, making them attractive targets. As Lazarus adapts, the biggest risk may not be unknown vulnerabilities but known ones that are not fully addressed. The Kelp exploit demonstrates how exposed the ecosystem remains to familiar weaknesses, especially when security is treated as a recommendation rather than a requirement. With attackers moving faster, this gap is becoming both easier to exploit and more expensive to ignore.