{"answers":{"affected":"1 open source package ship an affected version, including css-field-sizing-polyfill.","exploited":"There is no known exploitation of MAL-2026-17478 in the wild and no public exploit code.","fix":"Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.","what":"MAL-2026-17478 is a malicious package in css-field-sizing-polyfill, published on 4 Oct 2026."},"fix_prompt":"MAL-2026-17478 is a malicious package: css-field-sizing-polyfill (npm). Every version was published to cause harm.\n\nTask:\n1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.\n2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.\n3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.\n4. If the package is not used anywhere, say so and change nothing.\n\nReference: https://insights.sbomify.com/MAL-2026-17478/ (Markdown: https://insights.sbomify.com/MAL-2026-17478/index.md)","id":"MAL-2026-17478","markdown":"https://insights.sbomify.com/MAL-2026-17478/index.md","name":"MAL-2026-17478","record":{"aliases":[],"analysis":null,"analysis_generated_by":null,"assigner":null,"cpe":[],"cvss":{"score":null,"severity":null,"source":null,"vector":null,"version":null},"cwes":[],"description":"The package advertises itself as a CSS field-sizing polyfill but ships thunderboltRegistry.js, which runs an IIFE at module load time. The IIFE shells out via child_process.execSync to run `id`, `whoami`, `uname -a`, `ifconfig`/`ip addr`, and `cat /etc/hosts`, then transmits the collected output together with hostname, Node version, platform, and pid as query-string parameters to the hardcoded plaintext endpoint http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f. The module also exports proxied stubs for Wix-internal names (`thunderboltRegistry`, `siteAssetsRegistry`, `documentManagementRegistry`, `editorRegistry`, `corvidRegistry`) and ships a `registry-manifest.min.json` pointing at `static.parastorage.com`, indicating a dependency-confusion impersonation of Wix internal packages so that an internal resolver pulling this public name will trigger the beacon. The reconnaissance behavior is unrelated to the declared CSS polyfill purpose and fires on any `require()` of the package.","ecosystems":["npm"],"exploits":{"exploitdb":null,"first_seen":null,"github_poc":null,"max_poc_stars":null,"metasploit":null,"nuclei":null,"refs":[],"tier":null},"has_fix":false,"headline":"Malicious code in css-field-sizing-polyfill (npm)","id":"MAL-2026-17478","indexable":true,"kev":null,"kind":"malicious","links":{"ecosystem":"npm","product":null,"products":[],"type":null,"year":"2026"},"n_packages":1,"n_references":null,"packages":[{"ecosystem":"npm","fixed":[],"introduced":[],"last_affected":[],"package":"css-field-sizing-polyfill","purl":"pkg:npm/css-field-sizing-polyfill","source":"MAL-2026-17478"}],"products":null,"published":"2026-10-04","related":[],"sources":[{"class":"attribution","licence":"Apache-2.0","name":"OpenSSF Malicious Packages","prefix":"MAL"}],"ssvc":{"automatable":null,"exploitation":null,"technical_impact":null},"state":null,"updated":null,"vendors":null},"summary":null,"url":"https://insights.sbomify.com/MAL-2026-17478/"}