Threats Tagged 'easy-day-js'

Microsoft Threat Intelligence discovered a large-scale npm supply chain attack compromising over 140 packages in the mastra and @mastra scopes. The attack originated from takeover of the ehindero npm maintainer account, which published poisoned package versions introducing easy-day-js, a malicious typosquat of the popular dayjs library. The malicious package executed a postinstall hook that deployed an obfuscated dropper script, disabled TLS certificate verification, contacted command-and-control infrastructure at 23.254.164.92 and 23.254.164.123, and downloaded a second-stage payload. This 41KB cross-platform Node.js implant installed persistence mechanisms, performed cryptocurrency wallet inventory, exfiltrated browser history and host reconnaissance data, and on Windows performed reflective .NET assembly injection for fileless in-memory code execution. Any developer workstation or CI/CD pipeline executing npm install after compromise was potentially exposed regardless of code usage.

More than 140 Mastra npm packages were compromised through a supply chain attack that injected a typosquatted dependency called easy-day-js. A single npm account published malicious versions within a short timeframe, affecting packages including @mastra/core with over 918K weekly downloads. The attack executes during npm install via a postinstall hook, deploying a two-stage payload. The first stage disables TLS validation and downloads a second-stage implant that installs cross-platform persistence on Windows, macOS, and Linux. This implant functions as a command-and-control client that steals cryptocurrency wallet inventories from 166+ browser extensions, harvests browser history, and can execute arbitrary code sent by operators. The malicious code executes before developers import packages, compromising systems during installation.