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

Barely three weeks after North Korea-affiliated hackers utilized social engineering to breach the cryptocurrency trading firm Drift, it appears that hackers linked to the nation have successfully carried out another significant exploit, this time targeting Kelp. The attack on Kelp, a restaking protocol integrated into LayerZero's cross-chain infrastructure, signifies an evolution in the operational tactics of North Korea-linked hackers. Instead of merely seeking out bugs or exploiting stolen credentials, they are now manipulating the fundamental assumptions built into decentralized systems. The combined impact of these two incidents points to a more organized and structured approach than isolated, one-off hacks, as North Korea continues to escalate its efforts to divert 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; rather, 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 exploit highlights a critical issue with the system's configuration, where it relied on a single verifier to approve cross-chain messages, a choice that, while faster and simpler to set up, 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 on this, stating that LayerZero's default setup was to have a single verifier. David Schwed, COO of blockchain security firm SVRN, 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 aftermath of the exploit has not been contained to Kelp, as its assets are utilized across multiple platforms, leading to a wider impact, including lending platforms like Aave that accepted the affected assets as collateral now dealing with losses. This turns a single exploit into a broader stress event. The attack also reveals a disparity 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 expanded on this, 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 essence, even systems that appear decentralized can have vulnerabilities, particularly in less visible layers such as data providers or infrastructure, which are increasingly the focus of attackers. This shift may explain the recent targeting by Lazarus, a group that has begun focusing on 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 underlying more visible applications, and they tend to hold large amounts of value, making them attractive targets. If earlier waves of crypto hacks focused on exchanges or obvious code flaws, recent activity suggests a move toward what could be called the industry's plumbing, 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 demonstrated 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.