North Korea's Cryptocurrency Hacking 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 carried out, this time on 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 now exploiting 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. 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 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.' This means the system checked the sender of the message but not the correctness of the message itself. For security experts, this exploit highlights the issue of exploiting how a system is set up rather than discovering a 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 exploit, LayerZero recommended using multiple independent verifiers to approve transactions, similar to requiring multiple signatures on a bank transfer. However, some have pushed back on this recommendation, 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 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 incident also exposes 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 further clarified, '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.' This means that even systems that appear decentralized can have weak points, especially in less visible layers such as data providers or infrastructure, which are increasingly the focus of attackers. The recent targeting by Lazarus, a group linked to North Korea, of cross-chain and restaking infrastructure, underscores this shift. These layers are critical but complex and often 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 towards targeting the industry's underlying infrastructure, which is harder to monitor and easier to misconfigure. As Lazarus adapts, 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 ones, 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.