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

Less than three weeks after hackers linked to North Korea used social engineering to target the cryptocurrency trading firm Drift, another major exploit was carried out against Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests an evolution in the tactics used by North Korea-linked hackers, who are no longer just looking for vulnerabilities or stolen credentials but are also exploiting the fundamental assumptions underlying decentralized systems. The combined impact of these two incidents points to a more organized effort by North Korea to intercept 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.' More than $500 million was siphoned off in just over two weeks across the Drift and Kelp exploits. The Kelp breach did not involve breaking encryption or cracking keys; instead, attackers manipulated the data fed into the system, forcing it to rely on compromised inputs and approve transactions that did not actually occur. As Urbelis noted, 'The security failure is simple: a signed lie is still a lie. Signatures guarantee authorship; they do not guarantee truth.' In simpler terms, the system checked who sent the message, not whether the message itself was correct. For security experts, this is less about a new, sophisticated hack and more about exploiting how the system was set up. David Schwed, COO of blockchain security firm SVRN, observed, 'This attack wasn't about breaking cryptography; it was about exploiting how the system was set up.' A key issue was a configuration choice: Kelp relied on a single verifier to approve cross-chain messages, which is faster and simpler to set up but removes a critical safety layer. In response, LayerZero has recommended using multiple independent verifiers to approve transactions, similar to requiring multiple signatures on a bank transfer. However, some in the ecosystem have pushed back against this recommendation, stating 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 documentation and getting it right is not realistic.' The impact of the exploit has not been limited 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 attack also highlights a gap between the marketing of decentralization and its actual implementation. As 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, 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 begun targeting cross-chain and restaking infrastructure, the parts of the cryptocurrency space that move assets between systems or allow them to be reused. These layers are critical but complex, often sitting beneath more visible applications, and they tend to hold large amounts of value, making them attractive targets. If earlier waves of cryptocurrency hacks focused on exchanges or obvious code flaws, recent activity suggests a move toward targeting 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 showed how exposed the ecosystem remains to familiar vulnerabilities, 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.