{"id":"MAL-2026-12615","summary":"Malicious code in claims-fixtures-shared (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (291919ef20015ad326b92c506f2df9e710e72e659499bfd240c9b6453bf0fd82)\nOn require('claims-fixtures-shared'), index.js loads _helpers.js which immediately calls init(). init() reconstructs four Cloudflare Workers hostnames (oob-worker.cf101-adf.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev) and a set of DNS TXT-record resolvers (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) via runtime array.join(\"\") to evade static string scanners, then downloads a per-platform binary via https.get, writes it to /tmp or %TEMP% under a masquerading filename (.cache_\u003crnd\u003e on unix, dotnet_diag_\u003crnd\u003e.exe on Windows), fs.chmodSync 0o755, and spawns it detached via /bin/sh -c or cmd. No signature or hash verification is performed despite a '// SHA-256 integrity check' cover-story comment; a DNS TXT-record fallback channel and a.analytics_state lock file for rerun throttling are present. The package's stated purpose is a trivial fixtures helper, unrelated to any native binary. Env-var opt-outs (DISABLE_TELEMETRY, DO_NOT_TRACK) frame the code as telemetry while it stages and executes an arbitrary attacker-controlled payload.\n","modified":"2026-08-05T14:35:50.877932570Z","published":"2026-08-05T14:05:36Z","database_specific":{"malicious-packages-origins":[{"import_time":"2026-08-05T14:20:08.16829282Z","modified_time":"2026-08-05T14:05:36Z","sha256":"291919ef20015ad326b92c506f2df9e710e72e659499bfd240c9b6453bf0fd82","source":"amazon-inspector","versions":["35.8.6"],"id":"IN-MAL-2026-015160"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/claims-fixtures-shared/v/35.8.6"}],"affected":[{"package":{"name":"claims-fixtures-shared","ecosystem":"npm","purl":"pkg:npm/claims-fixtures-shared"},"versions":["35.8.6"],"database_specific":{"indicators":{"package_integrity":[{"hashes":{"sha1":"ff8fc9083abd8d3c8a7aa21e136433e92807d26c","sha512_sri":"sha512-qADl+WfhVIo2XE63EK2qk4d/1XIWy8gZ4woC0JJPfEmM5mYBp5LtAEavUdnCBJCEjOkZbhMWwKvy02JzqjG6OQ=="},"filename":"claims-fixtures-shared-35.8.6.tgz"}],"evidence_files":[{"sha256":"f3848197acb5dfbf1f7123cfbc00a859db2fc652489b4dca299628ab79dcacce","tlsh":"79a1855a06ba70194bb0dbe4871b4416f65bf6533280c6c4f7ac69985f7312483b2efc","path":"_helpers.js"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-fixtures-shared/MAL-2026-12615.json","cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}]}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}