Description

A North Korea-linked hacking group has been detected using the EtherHiding technique to spread malware and steal cryptocurrency, marking the first time a state-sponsored threat actor has adopted this approach. Google’s Threat Intelligence Group (GTIG) attributed the operation to UNC5342, also known by names such as CL-STA-0240 (Palo Alto Networks), DeceptiveDevelopment (ESET), Famous Chollima (CrowdStrike), and Void Dokkaebi (Trend Micro). The campaign, called Contagious Interview, targets developers and IT professionals on LinkedIn under the guise of recruitment. Once the attackers move the conversation to Telegram or Discord, victims are tricked into executing malicious code disguised as a job test. The operation’s goal mirrors North Korea’s ongoing efforts in cyber espionage and financial theft, granting attackers access to victims’ systems to steal sensitive data and digital assets. Since February 2025, GTIG has observed the group embedding harmful code in smart contracts hosted on BNB Smart Chain and Ethereum, using the blockchain as a decentralized delivery channel. This design makes it nearly impossible to take down or trace, as blockchain transactions obscure the deployer’s identity. The attackers can also modify their payloads by updating smart contracts at a minimal gas fee, ensuring persistence and flexibility across campaigns. According to Mandiant’s Robert Wallace, this marks a dangerous evolution in cyber tactics, showing that nation-state actors are now leveraging decentralized technology to develop resilient and adaptive malware distribution systems. The infection chain is multi-stage and targets Windows, macOS, and Linux devices using components like a malicious npm downloader, BeaverTail (information stealer), and JADESNOW, which fetches InvisibleFerret, a JavaScript backdoor for remote control and data theft. Google warned that EtherHiding introduces a new era of “bulletproof” hosting, where blockchain technology is exploited for malicious purposes, emphasizing the continuous evolution of state-sponsored cyber threats.