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 significant exploit has been carried out against 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 now exploiting fundamental assumptions built into decentralized systems, rather than just looking for bugs or stolen credentials. The two incidents combined 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 stolen across the Drift and Kelp exploits in just over two weeks, highlighting the scale of the issue. The Kelp exploit 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 occurred. This security failure is attributed to the system's design, where it checked the sender's identity but not the truthfulness of the message. Experts view this as exploiting how the system was set up rather than a sophisticated new hack. A key issue was the configuration choice to rely 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, 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 not be on users to configure for security. The impact has not been limited to Kelp, as its assets are used across multiple platforms, and problems can spread, affecting lending platforms like Aave that accepted the impacted assets as collateral. This situation highlights a chain of IOUs, where the chain's strength is only as good as the controls on each link. When one link breaks, others are affected, turning a single exploit into a broader stress event. The attack also reveals a gap between the marketing of decentralization and its actual implementation. Experts argue that true decentralization is not just about the absence of central points but a series of choices, and the stack is only as strong as its most centralized layer. This means even seemingly decentralized systems can have weak points, particularly in less visible layers like 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 are critical for moving assets between systems or allowing them to be reused and tend to hold large amounts of value, making them attractive targets. The shift in hacking efforts towards the 'plumbing' of the crypto industry, the systems that connect everything together but are harder to monitor and easier to misconfigure, may explain Lazarus' recent strategies. As Lazarus adapts, 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.