MAL-2026-10189: Malicious code in tinymask-js (npm)
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (dc1d083feee4cace9dba5cabdfd74701c7dc093520f0bbc104858ab699203604) index.js (declared as the package main) reconstructs a host, URL paths, and dropped filenames from String.fromCharCode numeric arrays, resolving to https://filament-zap.vercel.app/service/assets/fetchBinary and /fetchLinuxBinary. On require, it downloads an OS-specific binary over HTTPS, writes it to %LOCALAPPDATA%\Programs\WinMetrics\WinService.exe on Windows or ~/.local/share/WinMetrics on Linux, chmods it 0755 on Linux, and spawns it detached with stdio ignored and windowsHide set. The binary is fetched from a non-publisher host, is not pinned or hash/signature-verified, and its cover-story naming ('WinMetrics', 'WinService.exe') is unrelated to the package's advertised input-masking purpose. The package name mirrors the legitimate 'tinymask' package, declares 'tinymask': '*' as a dependency, and ends index.js with module.exports = require('tinymask'), so consumers who mistype the name receive real tinymask functionality alongside the hidden dropper.
MAL-2026-10189: Malicious code in tinymask-js (npm)
Description
--- _-= Per source details. Do not edit below this line.=-_ ## Source: amazon-inspector (dc1d083feee4cace9dba5cabdfd74701c7dc093520f0bbc104858ab699203604) index.js (declared as the package main) reconstructs a host, URL paths, and dropped filenames from String.fromCharCode numeric arrays, resolving to https://filament-zap.vercel.app/service/assets/fetchBinary and /fetchLinuxBinary. On require, it downloads an OS-specific binary over HTTPS, writes it to %LOCALAPPDATA%\Programs\WinMetrics\WinService.exe on Windows or ~/.local/share/WinMetrics on Linux, chmods it 0755 on Linux, and spawns it detached with stdio ignored and windowsHide set. The binary is fetched from a non-publisher host, is not pinned or hash/signature-verified, and its cover-story naming ('WinMetrics', 'WinService.exe') is unrelated to the package's advertised input-masking purpose. The package name mirrors the legitimate 'tinymask' package, declares 'tinymask': '*' as a dependency, and ends index.js with module.exports = require('tinymask'), so consumers who mistype the name receive real tinymask functionality alongside the hidden dropper.
Affected software
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Technical Details
- Gcve Source
- db.gcve.eu
- Osv Id
- MAL-2026-10189
- Osv Schema Version
- 1.7.4
- Aliases
- []
- Ecosystems
- ["npm"]
- Database Specific Severity
- null
- Cvss Version
- null
Threat ID: 6a535bfc68715ace43ad5135
Added to database: 07/12/2026, 09:18:52 UTC
Last updated: 07/12/2026, 09:18:52 UTC
Views: 1
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