{"schema_version":"1.8.0","id":"MAL-2026-12608","published":"2026-08-05T14:06:34Z","modified":"2026-08-05T14:35:46.966753691Z","summary":"Malicious code in claims-auth-domain (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (689620689df62b0e31d3caeb29327b88da40bae2bb66da3075dde6ee311ea6c3)\nOn require('claims-auth-domain'), index.js loads _vendor.js which selects a platform-specific endpoint, downloads a binary from hardcoded attacker infrastructure, stages it under /tmp or %TEMP% with a disguised name ('.cache_<hex>' on Unix, 'dotnet_diag_<hex>.exe' on Windows), sets it executable via chmod 0755, and spawns it detached via /bin/sh or cmd. Destination hostnames are assembled by concatenating split string fragments (e.g. ['oob-worker.cf101-ad','f.work','ers','.d','ev'].join('')) to hide the C2 domains from static inspection. If HTTPS delivery from *.workers.dev fails, _vendor.js falls back to reassembling the payload from chunked DNS TXT records under *.dl.wel1.ru: a count is fetched from c.<domain>, then N.<domain> TXT chunks are base64-decoded and concatenated into the executable. Cover-story framing labels the code as telemetry/analytics and honors DISABLE_TELEMETRY / DO_NOT_TRACK env vars to reduce detection. The result on any host that installs and loads this package is import-time full-host code execution under attacker control.\n","affected":[{"package":{"name":"claims-auth-domain","ecosystem":"npm","purl":"pkg:npm/claims-auth-domain"},"versions":["35.5.4"],"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":[{"path":"_vendor.js","sha256":"98aa24637f499852f29c9f5063675422878305a615c9efc0e6e065fb65749fba","tlsh":"efb1746a166971188b70d7e486175016f66af6633690c5d8f69c68881fb3228c3b2efc"}],"package_integrity":[{"filename":"claims-auth-domain-35.5.4.tgz","hashes":{"sha1":"b33c20a018484b46fe042fb878cbabeb40ea2c52","sha512_sri":"sha512-guSw9tN5dW7bRGdCUMMA6KrEYDI1SHe6oFxFsunimIMs8dZ4hjJSW6rkWNkS/y+0Pi6Y3UXLaSg81UUxDjUatg=="}}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/claims-auth-domain/MAL-2026-12608.json"}}],"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/claims-auth-domain/v/35.5.4"}],"database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-015167","import_time":"2026-08-05T14:20:08.838432283Z","modified_time":"2026-08-05T14:06:34Z","sha256":"689620689df62b0e31d3caeb29327b88da40bae2bb66da3075dde6ee311ea6c3","source":"amazon-inspector","versions":["35.5.4"]}]},"credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}