North Korea's Crypto Theft Tactics Are Evolving, Targeting DeFi

Less than three weeks after North Korea-linked hackers targeted crypto trading firm Drift using social engineering, another major exploit has been carried out, this time on Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This suggests an evolution in the tactics of North Korea-linked hackers, who are no longer just exploiting bugs or using stolen credentials, but are now manipulating the fundamental assumptions built into decentralized systems. The combined incidents point to a more organized effort by North Korea to hijack crypto sector funds, rather than 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 stolen across 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. The security failure lies in the system's design, where it checks the sender's identity but not the truth of the message. Experts consider this less about a new hack and more about exploiting the system's setup. The attack on Kelp highlights a configuration issue, where the system relied on a single verifier to approve cross-chain messages, removing a critical safety layer. In response, LayerZero has recommended using multiple independent verifiers, similar to requiring multiple signatures on a bank transfer. However, some argue that LayerZero's default setup was to have a single verifier, and that security should not depend on users reading documentation correctly. The impact of the Kelp exploit has not been limited to Kelp itself, as its assets are used across multiple platforms, causing problems to spread. Lending platforms like Aave, which accepted the impacted assets as collateral, are now dealing with losses, turning a single exploit into a wider stress event. The attack also exposes the gap between the marketing of decentralization and its actual implementation. As Urbelis puts it, '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. The recent targeting by Lazarus, a group linked to North Korea, has shifted towards cross-chain and restaking infrastructure, which are critical but complex and often hold large amounts of value. This shift may explain the move towards targeting the 'plumbing' of the crypto industry, the systems that connect everything together but are 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, and the gap between security recommendations and requirements is becoming both easier to exploit and more expensive to ignore.