North Korea's Crypto Attack Strategy Expands, Targeting DeFi

Less than three weeks after North Korea-linked hackers used social engineering to breach crypto trading firm Drift, another major exploit has been carried out on Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests an evolution in the tactics of North Korea-linked hackers, who are now exploiting fundamental assumptions built into decentralized systems, rather than just looking for bugs or stolen credentials. The combined incidents point to a more organized effort by North Korea to hijack crypto funds. 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 exploit 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 simple: a signed lie is still a lie,' Urbelis said. 'Signatures guarantee authorship; they do not guarantee truth.' This means the system checked who sent the message, not whether the message itself was correct. For security experts, this is less about a new hack and more about exploiting how the system was set up. 'This attack wasn’t about breaking cryptography,' said David Schwed, COO of blockchain security firm SVRN. 'It was about exploiting how the system was set up.' A key issue was a configuration choice, with Kelp relying on a single verifier to approve cross-chain messages, which is faster and simpler but removes a critical safety layer. LayerZero has since recommended using multiple independent verifiers to approve transactions. The fallout has not stayed limited to Kelp, as its assets are used across multiple platforms, and problems can spread. '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, and in this case, lending platforms like Aave that accepted the impacted assets as collateral are now dealing with losses. The attack exposes a gap between how decentralization is marketed and how it actually works. 'A single verifier is not decentralized,' Schwed said. 'It’s a centralized decentralized verifier.' Urbelis puts it more broadly, '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 systems that appear decentralized can have weak points, especially in less visible layers like data providers or infrastructure. The group has begun targeting cross-chain and restaking infrastructure, the parts of crypto that move assets between systems or allow them to be reused. 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; it showed how exposed the ecosystem remains to familiar ones, especially when security is treated as a recommendation rather than a requirement.