{"answers":{"affected":"1 open source package ship an affected version, including css-mpmdds-polyfill.","exploited":"There is no known exploitation of MAL-2026-17554 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-2026-17554 is a malicious package in css-mpmdds-polyfill, published on 5 Oct 2026."},"fix_prompt":"MAL-2026-17554 is a malicious package: css-mpmdds-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-2026-17554/ (Markdown: https://insights.sbomify.com/MAL-2026-17554/index.md)","id":"MAL-2026-17554","markdown":"https://insights.sbomify.com/MAL-2026-17554/index.md","name":"MAL-2026-17554","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 presents itself as a CSS polyfill but ships thunderboltRegistry.js which runs an IIFE at module load. The IIFE acquires child_process via multiple fallbacks (require('child_process'), require('node:child_process'), and a synthesized Module constructor), executes shell commands to collect host identity (id, whoami, uname -a, ifconfig/ip addr, /etc/hosts) along with os.hostname, Node version, platform and pid, and transmits each result via fetch() as query parameters to the hardcoded endpoint http://dxpoc.gt.tc/callback.php/bb8968d0f67000433bf7005dd5ad2d1f over plaintext HTTP to a free-DNS (gt.tc) host unrelated to any CSS polyfill functionality. The IIFE also enumerates require.cache and deletes entries containing 'thunderboltRegistry' so the payload re-executes on every require rather than being memoized. registry-manifest.min.json maps multiple Wix/thunderbolt internal registry module names (siteAssetsRegistry.js, editorRegistry.js, and others) all to the same thunderboltRegistry.js payload mirrored on static.parastorage.com's unpkg mirror, consistent with a dependency-confusion / typosquat targeting the Wix thunderbolt ecosystem. The package stubs a Wix-ecosystem API surface via Proxy to appear functional while the exfil IIFE runs. The package name resembles a CSS polyfill but the shipped behavior is host reconnaissance and exfiltration with cache-busting evasion.","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-mpmdds-polyfill (npm)","id":"MAL-2026-17554","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-mpmdds-polyfill","purl":"pkg:npm/css-mpmdds-polyfill","source":"MAL-2026-17554"}],"products":null,"published":"2026-10-05","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-2026-17554/"}