North Korea's Cryptocurrency Theft Strategy is Evolving, with DeFi Being Repeatedly Targeted

Less than three weeks after hackers linked to North Korea used social engineering to breach the cryptocurrency trading firm Drift, it appears that hackers tied to the nation have successfully carried out another significant exploit, this time targeting Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests that North Korea-linked hackers are evolving their tactics, moving beyond exploiting bugs or stolen credentials to manipulating the fundamental assumptions underlying decentralized systems. The combined incidents of the Drift and Kelp exploits, resulting in the theft of over $500 million in just over two weeks, point to a more organized effort by North Korea to hijack 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.' 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 actually occurred. Urbelis noted, 'The security failure is simple: a signed lie is still a lie. Signatures guarantee authorship; they do not guarantee truth.' This means the system verified who sent the message but not whether the message itself was accurate. For security experts, this exploit highlights the vulnerability of systems based on how they are set up rather than a sophisticated new hack. David Schwed, COO of blockchain security firm SVRN, stated, '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 Kelp relying on a single verifier to approve cross-chain messages, which, although faster and simpler to set up, removes a critical safety layer. Following the incident, LayerZero recommended using multiple independent verifiers to approve transactions, akin to requiring multiple signatures on a bank transfer. However, some in the ecosystem have argued that LayerZero’s default setup was to have a single verifier. Schwed emphasized, '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 contained to Kelp, as its assets are used across multiple platforms, 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 exposes a gap between the marketing of decentralization and its actual implementation. Schwed pointed out, 'A single verifier is not decentralized. It’s a centralized decentralized verifier.' Urbelis added, '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.' In practice, this means that even systems that appear decentralized can have weak points, particularly in less visible layers such as data providers or infrastructure, which are increasingly the focus of attackers. This shift may explain why Lazarus, a group linked to North Korea, has recently targeted cross-chain and restaking infrastructure, the parts of the crypto ecosystem that move assets between systems or allow them to be reused. These layers are critical but complex and often 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 vulnerabilities, especially when security is treated as a recommendation rather than a requirement. As attackers move faster, this gap is becoming both easier to exploit and far more expensive to ignore.