Hacker groups connected to the North Korean government have increasingly focused their efforts on decentralised finance (DeFi) platforms and users. On 3 September, the U.S. Federal Bureau of Investigation (FBI) issued a stark warning, highlighting the aggressive tactics these actors employ to exploit vulnerabilities in the crypto industry.
The FBI underscored that the Democratic People’s Republic of Korea (DPRK) has been conducting well-disguised social engineering attacks. These hackers carry out extensive reconnaissance, reviewing social media activity on professional platforms to identify potential targets within the DeFi community. According to the analytics firm Chainalysis, North Korean hackers were responsible for approximately $1 billion in crypto heists in 2023 alone, a year that saw a rise in the number of hacks despite a decline in the total fiat value stolen.
Notorious Groups Behind the Attacks
The Lazarus Group, a cyber unit presumed to work for the North Korean government, has become notorious for its highly sophisticated exploits. Since its inception in 2009, this group has been tied to some of the largest crypto and traditional financial system breaches, including the infamous $100 million Harmony Bridge hack and the $81 million attack on the Central Bank of Bangladesh in 2016.
These cybercriminals often rely on a specific strategy, dubbed the "Lazarus Formula." This begins with infiltrating a target’s system using attacks on vulnerable codebases or through watering hole attacks, where malware is planted on legitimate websites. Once an employee from the target organisation visits the compromised site, their system becomes infected. The hackers then deploy backdoors across the target’s network, ultimately allowing them to bypass security measures and steal funds.
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Social Engineering at the Core
North Korean hackers have employed social engineering as their main strategy for targeting DeFi platforms. This includes using phishing attempts to access private keys and planting malicious developers within DeFi teams. A recent high-profile example involved a presumed North Korean developer exploit in the game Munchables, built on Ethereum Layer 2. The hacker inserted a vulnerability in the contract, allowing control of up to 1 million ETH, draining $63 million from the protocol. Fortunately, the funds were later returned without a ransom.
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Widespread Impact on the DeFi Ecosystem
The Lazarus Group has infiltrated numerous DeFi protocols and traditional financial institutions alike, leveraging tactics such as phishing emails and the exploitation of vulnerable codebases. The stolen funds are often laundered through mixers like Tornado Cash, obscuring the origin of the cryptocurrency. Chainalysis, alongside other analytics firms, has traced interconnected wallets linked to these hacks, helping to map the extensive web of exploitation.
Onchain analyst ZachXBT has further exposed how North Korean hackers infiltrate DeFi teams. Using fake identities, they build up resumes and GitHub repositories to apply for roles within multiple projects. These fraudulent developers are estimated to be earning between $300,000 to $500,000 per month by working simultaneously across over 25 DeFi projects, using these fake credentials to evade detection.
While the scale of North Korean cyberattacks on DeFi platforms is concerning, the problem lies deeper than the losses themselves. As the DeFi space becomes a primary target, these attacks highlight ongoing security vulnerabilities that could threaten the integrity of the entire decentralised ecosystem. The growing sophistication of social engineering tactics employed by these hackers means the problem may only worsen without adequate defences.