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

Less than three weeks after hackers linked to North Korea used social engineering to breach the crypto trading firm Drift, another significant exploit has been carried out against Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests a shift in tactics by North Korea-linked hackers, who are no longer just exploiting bugs or stolen credentials but are now targeting the fundamental assumptions underpinning decentralized systems. The combined impact of these incidents points to a more organized effort by North Korea to hijack funds from the crypto sector, rather than a series of isolated hacks. 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 fed into the system, forcing it to rely on compromised inputs and approve transactions that did not actually occur. 'The security failure is simple: a signed lie is still a lie,' Urbelis noted. 'Signatures guarantee authorship; they do not guarantee truth.' This exploit highlights a problem not with the cryptography itself but with how the system was set up, particularly in its reliance on a single verifier to approve cross-chain messages, a configuration choice that removed a critical safety layer. The fallout from this exploit has extended beyond Kelp, affecting lending platforms like Aave that accepted the impacted assets as collateral, turning a single exploit into a broader stress event. The incident also reveals a disconnect between the marketing of decentralization and its actual implementation. 'A single verifier is not decentralized,' said David Schwed, COO of blockchain security firm SVRN. 'It’s a centralized decentralized verifier.' Urbelis added, '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 shift in attackers' focus towards these layers, such as cross-chain and restaking infrastructure, may explain the recent targeting by Lazarus. These layers are critical but complex and often 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, indicating a gap in security that is becoming both easier to exploit and more expensive to ignore.