North Korea's Cryptocurrency Theft Tactics Are Evolving, With DeFi Being Repeatedly Targeted

Barely three weeks after hackers linked to North Korea used social engineering to breach the crypto trading firm Drift, it appears that hackers tied to the nation have executed another significant exploit, this time targeting Kelp, a restaking protocol interconnected with LayerZero's cross-chain infrastructure. This attack suggests an evolution in the tactics employed by North Korea-linked hackers, who are no longer solely focused on identifying bugs or exploiting stolen credentials but are now manipulating the fundamental assumptions underlying decentralized systems. The cumulative effect of these incidents points to a more organized effort by North Korea to commandeer funds from the cryptocurrency sector, rather than a series of 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 Drift and Kelp exploits collectively resulted in the theft of over $500 million in just over two weeks. 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 thereby approving transactions that never actually occurred. 'The security failure is simple: a signed lie is still a lie,' Urbelis noted. 'Signatures guarantee authorship; they do not guarantee truth.' In essence, the system verified the sender of the message but not the accuracy of the message itself, a distinction that security experts view as exploiting the system's setup rather than discovering a novel hack. David Schwed, COO of blockchain security firm SVRN, emphasized, 'This attack wasn’t about breaking cryptography; it was about exploiting how the system was set up.' A key issue was the configuration choice to rely on a single verifier to approve cross-chain messages, a decision made for speed and simplicity but one that 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 pushed back against this recommendation, arguing that LayerZero's default setup was to use a single verifier. Schwed argued, '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 utilized across multiple platforms, leading to a ripple effect where problems can spread. 'These assets are a chain of IOUs,' Schwed explained. 'And the chain is only as strong as the controls on each link.' When one link breaks, others are affected, resulting in lending platforms like Aave, which accepted the impacted assets as collateral, now dealing with losses and transforming a single exploit into a broader stress event. The attack also highlights a discrepancy between the marketing of decentralization and its actual implementation. 'A single verifier is not decentralized,' Schwed stated. 'It’s a centralized decentralized verifier.' Urbelis expanded on this, saying, '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 appearing to be 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 might explain the recent targeting by Lazarus. The group has begun focusing on cross-chain and restaking infrastructure, Urbelis noted, the components of crypto that facilitate the movement of assets between systems or allow them to be reused. These layers are critical but complex, often underlying more visible applications, and they tend to hold significant value, making them attractive targets. If earlier waves of crypto hacks focused on exchanges or obvious code flaws, recent activity suggests a move toward what could be termed the industry’s underlying infrastructure, the systems that connect everything together but are harder to monitor and easier to misconfigure. 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 demonstrated how exposed the ecosystem remains to familiar ones, especially when security is treated as a recommendation rather than a requirement. And as attackers move faster, this gap is becoming both easier to exploit and far more expensive to ignore.