MAL-2026-17477 Malicious code in css-env-function-shim (npm)
Malicious package
Published
MAL-2026-17477 is a malicious package: css-env-function-shim (npm). Every version was published to cause harm.
Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.
Reference: https://insights.sbomify.com/MAL-2026-17477/ (Markdown: https://insights.sbomify.com/MAL-2026-17477/index.md)
- Package
- css-env-function-shim
- Registry
- npm
What is MAL-2026-17477?
MAL-2026-17477 is a malicious package in css-env-function-shim, published on 4 Oct 2026.
Official description
Package self-describes as a CSS env() shim but ships thunderboltRegistry.js, which runs an IIFE at module load that base64-decodes the strings 'child_process' and 'execSync', dynamically requires child_process, and shells out whoami, uname, cat /etc/hosts, ifconfig/ip addr, id, and hostname. The collected output is POSTed to a hardcoded webhook.site URL (webhook.site/0492a36c-4d7b-408a-865c-226db25987ba) and beaconed to a subdomain of davdpb8lhot13kgmnhp0863x9g83mpswq.oast.live for DNS exfiltration. All sensitive identifiers (module name, method name, commands, destination host, UUID path, OAST subdomain) are stored as base64 blobs or String.fromCharCode arrays and reconstructed at runtime to defeat static inspection. index.js is a stub; the module factory is re-exported under nine Wix-internal registry key names (thunderboltRegistry, siteAssetsRegistry, editorRegistry, corvidRegistry, and similar), and the shipped registry-manifest.min.json aliases numerous Wix thunderbolt *Registry.js URLs on parastorage.com to this package's thunderboltRegistry.js — a dependency-confusion lure targeting Wix's internal build so that any importer of those names triggers the exfiltration IIFE at require time.
What should I do about MAL-2026-17477?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.