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 attributed to the nation, this time targeting Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests an evolution in the tactics of North Korea-linked hackers, who are now exploiting fundamental assumptions in decentralized systems, rather than just seeking out bugs or stolen credentials. The two incidents combined indicate a more organized effort by North Korea to hijack funds from the crypto 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, highlighting the escalating efforts by North Korea to tap into the crypto sector for funds. The Kelp breach did not involve breaking encryption but rather manipulating the data feeding into the system, forcing it to rely on compromised inputs and thereby approving 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 was more about exploiting the system's setup rather than breaking cryptography, according to David Schwed, COO of blockchain security firm SVRN. A key issue was Kelp's reliance on a single verifier to approve cross-chain messages, a configuration choice that, while faster and simpler, removes a critical 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 on this, 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 docs and getting it right is not realistic.' The fallout from the exploit has not been contained 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. This incident also highlights 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, even seemingly decentralized systems 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 Lazarus, a group linked to North Korea, of cross-chain and restaking infrastructure underscores this shift. These layers, critical but complex and often less visible, are where assets are moved between systems or reused and tend to hold large amounts of value, making them attractive targets. 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, suggests that 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 adapt and move faster, this gap is becoming both easier to exploit and far more expensive to ignore.