North Korea's Cryptocurrency Hacking Strategy is Evolving, with DeFi Being a Frequent Target

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 carried out, this time targeting Kelp, a restaking protocol connected to LayerZero's cross-chain infrastructure. This attack suggests a shift in the tactics employed by North Korea-linked hackers, who are now exploiting fundamental assumptions built into decentralized systems, rather than just seeking out vulnerabilities or stolen credentials. The cumulative effect of these incidents points to a more organized effort by North Korea to intercept funds from the cryptocurrency sector, amounting to over $500 million stolen in just over two weeks across the Drift and Kelp exploits. 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.' The Kelp breach did not involve breaking encryption but rather manipulating the data input into the system, forcing it to rely on compromised data and approve transactions that did not actually occur. As explained by Urbelis, 'The security failure is simple: a signed lie is still a lie. Signatures guarantee authorship; they do not guarantee truth.' This exploit highlights a basic issue with the system's configuration, which relied on a single verifier to approve cross-chain messages, a setup 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 argue that LayerZero's default setup was to have a single verifier, and the onus should be on ensuring safe configurations rather than relying on users to read documentation and implement security measures correctly. David Schwed, COO of blockchain security firm SVRN, noted, '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 impact of the Kelp exploit has not been contained, as its assets are utilized across multiple platforms, leading to a wider stress event affecting lending platforms like Aave that accepted the impacted assets as collateral. This situation exposes a discrepancy between the marketing of decentralization and its practical implementation. As Schwed pointed out, 'A single verifier is not decentralized. It's a centralized decentralized verifier.' Urbelis expanded on this, saying, '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 weak points, particularly in less visible layers such as data providers or infrastructure, which are increasingly becoming 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 for moving assets between systems or allowing them to be reused, are complex, often under visible applications, and hold significant value, making them attractive targets. The evolution in hacking strategies, from targeting exchanges or obvious code flaws to focusing on the 'plumbing' of the crypto industry - the systems that connect everything together but are harder to monitor and easier to misconfigure - poses a significant risk. The Kelp exploit did not reveal a new vulnerability but highlighted how exposed the ecosystem remains to familiar weaknesses, especially when security is treated as a recommendation rather than a requirement. As attackers adapt and move faster, the gap between security measures and actual vulnerabilities is becoming both easier to exploit and more expensive to ignore.