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 cryptocurrency trading firm Drift, another major exploit has been carried out with Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests an evolution in the tactics used by 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 of Drift and Kelp point to a more organized effort by North Korea 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 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 actually occurred. 'The security failure is simple: a signed lie is still a lie,' Urbelis said. 'Signatures guarantee authorship; they do not guarantee truth.' This exploit highlights a configuration issue where Kelp relied on a single verifier to approve cross-chain messages, which, although faster and simpler to set up, removes a critical safety layer. In response, LayerZero has recommended using multiple independent verifiers to approve transactions. The fallout from the Kelp exploit has not been limited to Kelp itself, as its assets are used across multiple platforms, leading to a wider stress event affecting lending platforms like Aave that accepted the impacted assets as collateral. The incident also exposes a gap 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.' The shift in targeting by attackers like Lazarus towards cross-chain and restaking infrastructure, which are critical but complex and often less visible, indicates a move towards exploiting the 'plumbing' of the crypto industry. As these attackers adapt, the biggest risk may not be unknown vulnerabilities but known ones that are not fully addressed, with the gap between security recommendations and requirements becoming increasingly exploitable and expensive to ignore.