{"id":"MAL-2026-12613","summary":"Malicious code in claims-domain (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (f75c174b3db5e2480eabc7c7f8ab5e8366737fac8e76086da13f8acac6545813)\nOn require of the package, `index.js` loads `_ext.js`, which reconstructs destination hostnames from string-split arrays (e.g. `[\"oob-worker.cf99-9b3\",\".wor\",\"kers.\",\"dev\"].join(\"\")`) to build URLs at `oob-worker.cf99-9b3.workers.dev`, `oob-worker.cf103-070.workers.dev`, and `oob-worker.cf102-baf.workers.dev`, with a DNS TXT fallback to `sdk.dl.wel1.ru`, `ext.dl.wel1.ru`, `pkg.dl.wel1.ru`, and `net.dl.wel1.ru`. The fetched platform-specific binary is written to `/var/tmp` or the Windows temp directory under disguised filenames (`.cache_\u003chex\u003e`, `dotnet_diag_\u003chex\u003e.exe`), chmodded to 0755, and spawned detached via `/bin/sh -c` or `cmd /c start`. The `child_process` module and `fs.chmodSync` API are also referenced through string concatenation (`require(\"child_\" + \"process\")`, `fs[\"chmod\" + \"Sync\"]`) alongside cover-story comments describing the routine as an analytics/telemetry SDK. The package's advertised purpose (a claims-domain library) does not require fetching or executing native binaries from anonymous Cloudflare Workers subdomains, and the delivery is unpinned, unhashed, and obfuscated.\n","modified":"2026-08-05T14:35:49.645900646Z","published":"2026-08-05T14:05:44Z","database_specific":{"malicious-packages-origins":[{"import_time":"2026-08-05T14:20:08.305279533Z","modified_time":"2026-08-05T14:05:44Z","sha256":"f75c174b3db5e2480eabc7c7f8ab5e8366737fac8e76086da13f8acac6545813","source":"amazon-inspector","versions":["35.6.7"],"id":"IN-MAL-2026-015161"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/claims-domain/v/35.6.7"}],"affected":[{"package":{"name":"claims-domain","ecosystem":"npm","purl":"pkg:npm/claims-domain"},"versions":["35.6.7"],"database_specific":{"cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}],"indicators":{"evidence_files":[{"tlsh":"5db1b69a126670198bb09bf0c717581af65be6633780c2d8f75c69981fb612483b1efc","path":"_ext.js","sha256":"fc945fa7bb70385b7660edb2464d02ebfb8510cd1f7a4b11e357998b5ffa29e3"}],"package_integrity":[{"hashes":{"sha1":"11d42dc900bb6f69f01b8502887b96827738c8ec","sha512_sri":"sha512-CukXb45ZO/uXhCPV2Oh8y4Ksl2qSLIEHeM7hxh55aepNa7yUWRoHzDFnK2la1GQTD9IpVUWxsIgTwa5PymW5+Q=="},"filename":"claims-domain-35.6.7.tgz"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-domain/MAL-2026-12613.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}