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

Less than three weeks after North Korea-linked hackers used social engineering to breach the crypto trading firm Drift, hackers linked to the nation appear to have carried out another significant exploit with Kelp, a restaking protocol tied into LayerZero's cross-chain infrastructure. This suggests an evolution in the tactics employed by North Korea-linked hackers, who are now exploiting the 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 funds from the crypto 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 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 attributed to a signed lie being treated as truth, with signatures guaranteeing authorship but not the truthfulness of the message. The system checked who sent the message, not whether the message itself was correct. 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. The fallout from the exploit has extended beyond Kelp, affecting lending platforms like Aave that accepted the impacted assets as collateral, resulting in losses and turning a single exploit into a wider stress event. The attack also exposes a gap between the marketing of decentralization and its actual implementation, with a single verifier being considered centralized. As Urbelis notes, '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 shift in focus towards cross-chain and restaking infrastructure, which are critical but complex and often hold large amounts of value, may explain the recent targeting by Lazarus. The biggest risk may not be unknown vulnerabilities but known ones that are not fully addressed, as the Kelp exploit demonstrated how exposed the ecosystem remains to familiar weaknesses, especially when security is treated as a recommendation rather than a requirement.