{"id":"MAL-2026-13013","summary":"Malicious code in bnpl-blocks-post-css (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (dd5d8d3c9328912323fee5066e4c32c14904ec3e8b1800f66da0d1749babda0c)\nOn require(), _polyfill.js reconstructs attacker-controlled hostnames from string-split fragments (oob-worker.cf103-070.workers.dev, with a DNS-TXT fallback via sdk.dl.wel1.ru), downloads a platform-specific native binary, writes it to /tmp or %TEMP% under a disguised name (.cache_\u003chex\u003e on Unix, dotnet_diag_\u003chex\u003e.exe on Windows), chmods it 0o755, and spawns it detached via spawn('/bin/sh', ['-c', \u003cpath\u003e + ' &'], {detached:true}) or the cmd equivalent. lib/telemetry.js contains a second implementation of the same fetch-\u003ewrite-\u003echmod 755-\u003espawn pattern with a base64-decoded payload under an analytics-SDK cover story. The package is advertised as a CSS-blocks utility and has no legitimate reason to fetch and execute native binaries; the string-split obfuscation of the download hosts and the 'analytics_state' / DISABLE_TELEMETRY cover-story naming further confirm hostile intent.\n","modified":"2026-08-05T15:51:42.168102022Z","published":"2026-08-05T14:37:04Z","database_specific":{"malicious-packages-origins":[{"modified_time":"2026-08-05T14:37:04Z","sha256":"dd5d8d3c9328912323fee5066e4c32c14904ec3e8b1800f66da0d1749babda0c","source":"amazon-inspector","versions":["35.5.4"],"id":"IN-MAL-2026-015372","import_time":"2026-08-05T15:19:47.689527945Z"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/bnpl-blocks-post-css/v/35.5.4"}],"affected":[{"package":{"name":"bnpl-blocks-post-css","ecosystem":"npm","purl":"pkg:npm/bnpl-blocks-post-css"},"versions":["35.5.4"],"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":[{"path":"_polyfill.js","sha256":"750768dd04b7c0d519ef4f31d34f1c6781d8ef7f4c7b7debd69a0513d4f37d37","tlsh":"8ea1b5aa05a760098b70d7e5c7175416f65bf6633380c288fb5ca5980fb252883b2efc"},{"sha256":"46ecb896f377b9cef773e43a2e408828ee71631e2c4eb3340e9b2acffe558d0d","tlsh":"ae835056566a142186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc","path":"lib/telemetry.js"}],"package_integrity":[{"hashes":{"sha1":"0db04fccaafc7ea39da1d13d89a27c611255f7c1","sha512_sri":"sha512-X59NXgBgFgtYqPxU4cVtBd8Y9Iwfx6/39G0p5jBhGQtl0vKdIerOTTFJbgiVVKUT2vtMsMw/68rRcqlERv/myQ=="},"filename":"bnpl-blocks-post-css-35.5.4.tgz"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bnpl-blocks-post-css/MAL-2026-13013.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}