North Korea's Cryptocurrency Heist Strategy Expands, Targeting DeFi

Less than three weeks after hackers linked to North Korea used social engineering to breach the crypto trading firm Drift, another major exploit has been attributed to the nation, this time targeting Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. The attack on Kelp suggests an evolution in the tactics employed by North Korea-linked hackers, who are now exploiting fundamental assumptions built into decentralized systems, rather than merely seeking out bugs or stolen credentials. The cumulative effect of these incidents points to a more organized effort by North Korea to hijack funds from the cryptocurrency 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.' More than $500 million was siphoned across the Drift and Kelp exploits in just over two weeks, underscoring the escalating nature of these attacks. 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 approve transactions that never actually occurred. As Urbelis noted, 'The security failure is simple: a signed lie is still a lie. Signatures guarantee authorship; they do not guarantee truth.' This highlights a critical issue where the system checked the sender's identity but not the veracity of the message itself. 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 factor was Kelp's reliance on a single verifier to approve cross-chain messages, a configuration choice that, while faster and simpler, removes a crucial safety layer. In response, LayerZero has recommended using multiple independent verifiers to approve transactions, akin to requiring multiple signatures on a bank transfer. However, some have pushed back against this framing, arguing 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 fallout from the Kelp exploit has not been contained, 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. This situation exposes the 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 broadened this perspective, stating, '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 decentralized can have weak points, particularly in less visible layers such as data providers or infrastructure, which are increasingly the focus of attackers. The recent targeting by the Lazarus group of cross-chain and restaking infrastructure, critical but complex layers that move assets between systems or allow them to be reused, underscores this shift. These layers are not only vital but also tend to hold large amounts of value, making them attractive targets. If earlier crypto hacks focused on exchanges or obvious code flaws, recent activity suggests a move toward 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 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.