North Korea's Cryptocurrency Theft Tactics Are Evolving, with DeFi Being a Prime Target

Barely three weeks after North Korea-linked hackers used social engineering to breach the crypto trading firm Drift, hackers with ties to the nation have apparently carried out another significant exploit, this time targeting Kelp, a restaking protocol integrated into LayerZero's cross-chain infrastructure. This attack suggests an evolution in the tactics of North Korea-linked hackers, who are no longer just looking for vulnerabilities or stolen credentials but are exploiting the fundamental assumptions built into decentralized systems. The combined incidents of Drift and Kelp point to a more organized effort than a series of isolated hacks, as North Korea continues to escalate its attempts 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 off through the Drift and Kelp exploits 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 approve transactions that never 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 exploit highlights a gap between the marketing of decentralization and its actual operation. The attack also exposes the risks of configuration choices, such as relying on a single verifier for approving cross-chain messages, which, while faster and simpler to set up, removes a critical safety layer. In response, LayerZero has recommended using multiple independent verifiers, akin to requiring multiple signatures on a bank transfer. However, some have pushed back against this recommendation, arguing that LayerZero's default setup was to have a single verifier. The fallout from the Kelp exploit has extended beyond Kelp itself, as its assets are used across multiple platforms, leading to problems spreading across the ecosystem. David Schwed, COO of blockchain security firm SVRN, noted, 'These assets are a chain of IOUs, and the chain is only as strong as the controls on each link.' When one link breaks, others are affected, turning a single exploit into a wider stress event. This has implications for lending platforms like Aave, which accepted the impacted assets as collateral and are now dealing with losses. The attack on Kelp and its aftermath also underscore the gap between the marketing of decentralization and its operational reality. 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 that appear decentralized can have weak points, especially in less visible layers like 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 crypto that move assets between systems or allow them to be reused. These layers are critical but complex, often sitting underneath more visible applications, and they tend to 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; 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.