Description

UNC5142, a financially motivated threat actor, is using blockchain smart contracts to distribute information stealers like Atomic (AMOS), Lumma, Rhadamanthys (RADTHIEF), and Vidar, targeting both Windows and macOS systems. The attacks exploit compromised WordPress websites and EtherHiding, a technique that hides malicious code within blockchain transactions, such as those on the BNB Smart Chain. The attack involves a multi-stage JavaScript downloader called CLEARSHORT, injected into WordPress sites to interact with malicious blockchain contracts. These contracts employ a ClickFix tactic, tricking victims into running commands that infect their systems with stealer malware. On Windows, an HTA file is downloaded to run a PowerShell script that fetches the payload in memory. On macOS, a bash script uses curl to download and execute the malware. In November 2024, UNC5142 evolved its attack by adopting a three-smart contract system for greater flexibility, enabling easy updates to payloads without changing compromised websites. This architecture, based on a Router-Logic-Storage pattern, enhances the actor’s ability to evade detection and takedowns. By June 2025, around 14,000 WordPress sites were flagged for compromise. However, UNC5142’s activity halted in late July 2025, possibly signaling a shift in tactics. Organizations should secure WordPress sites, monitor blockchain activity, and educate users to avoid social engineering attacks.