{"id":"MAL-2026-12626","summary":"Malicious code in claims-is-mobile-layout (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (b964f402f05efc7be7776cd7f2255b889404ca7c83fb10a8efbb6b85d53f955b)\nOn require() of the package, index.js unconditionally loads./_vendor.js, which selects a platform-specific endpoint, downloads a native binary over HTTPS, writes it to /tmp/.cache_\u003chex\u003e on Linux/macOS or %TEMP%\\dotnet_diag_\u003chex\u003e.exe on Windows, chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe. Destination hostnames are assembled at runtime via Array.join over split string literals (e.g. 'oob-worker.cf102-baf.workers.dev' on anonymous Cloudflare Workers subdomains) to evade static URL/domain scanning. A DNS-TXT covert-channel fallback under *.dl.wel1.ru chunks a base64 payload across numbered TXT records, reassembles it, and decodes it as executable content. The dropped binary is staged under cover-story names ('analytics_state', 'dotnet_diag_*') that do not match the package's advertised 'mobile layout' purpose.\n","modified":"2026-08-05T14:35:55.762251201Z","published":"2026-08-05T14:03:26Z","database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-015146","import_time":"2026-08-05T14:20:06.902533249Z","modified_time":"2026-08-05T14:03:26Z","sha256":"b964f402f05efc7be7776cd7f2255b889404ca7c83fb10a8efbb6b85d53f955b","source":"amazon-inspector","versions":["35.4.3"]}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/claims-is-mobile-layout/v/35.4.3"}],"affected":[{"package":{"name":"claims-is-mobile-layout","ecosystem":"npm","purl":"pkg:npm/claims-is-mobile-layout"},"versions":["35.4.3"],"database_specific":{"cwes":[{"description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code","cweId":"CWE-506"}],"indicators":{"evidence_files":[{"tlsh":"dea187aa05a670088bb0d7e4c7175416f65bf66373809288fbac65981fb611483f2efc","path":"_vendor.js","sha256":"f367efac38ed9baed7604fa64e748406eb02b11c946ddad5430c56950f6ecd30"}],"package_integrity":[{"hashes":{"sha1":"eed7e65d00e644eaba039893eca118769bfe1b75","sha512_sri":"sha512-T8MVjVtnQargFJhlGKkdyMGuGcHHLSfbUouv6P0XE/XGTMZoHUX4wkNFSeZqwrrWoPeep0sPWVfin0TPDcpOcw=="},"filename":"claims-is-mobile-layout-35.4.3.tgz"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-is-mobile-layout/MAL-2026-12626.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}