{"id":"MAL-2026-13047","summary":"Malicious code in boxy-fixture-pfa (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (0a15e41a397b63d04216419ddd8ec88f37cb68c5d35997ad840543e034f87d8f)\nOn require() of the package, _polyfill.js downloads a platform-specific binary from hardcoded destinations reassembled at runtime from split-string arrays (oob-worker.cf1006.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf103-070.workers.dev), writes it to /tmp under a hidden name (.cache_\u003chex\u003e) or to %TEMP%\\dotnet_diag_\u003chex\u003e.exe on Windows, chmods it 0755, and spawns it detached via /bin/sh -c '\u003cpath\u003e &' or cmd.exe /c start /b. A DNS-TXT fallback channel reassembles a base64 payload from chunked TXT records under *.dl.wel1.ru when HTTPS is blocked. The dropped binary is disguised with system-daemon-style filenames (dotnet_diag_,.cache_,.analytics_state) and the code carries opt-out checks on DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK as cover framing. A second dropper module lib/telemetry.js (81 KB, labeled 'Analytics SDK') ships the same base64-decode -\u003e filesystem write -\u003e chmod 0755 -\u003e cp.spawn('/bin/sh', ['-c', filePath + ' &']) chain with split-property-name obfuscation (child_'+'process, chmod'+'Sync); it is not referenced from index.js in this version but is present in the tarball as an alternate loader. Installing or importing this package results in arbitrary attacker-controlled code execution on the host.\n","modified":"2026-08-05T15:51:57.329564519Z","published":"2026-08-05T14:31:10Z","database_specific":{"malicious-packages-origins":[{"versions":["35.3.4"],"id":"IN-MAL-2026-015332","import_time":"2026-08-05T15:19:45.345446041Z","modified_time":"2026-08-05T14:31:10Z","sha256":"0a15e41a397b63d04216419ddd8ec88f37cb68c5d35997ad840543e034f87d8f","source":"amazon-inspector"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/boxy-fixture-pfa/v/35.3.4"}],"affected":[{"package":{"name":"boxy-fixture-pfa","ecosystem":"npm","purl":"pkg:npm/boxy-fixture-pfa"},"versions":["35.3.4"],"database_specific":{"indicators":{"package_integrity":[{"hashes":{"sha1":"beec5ca41eea219e7f143a4c49daa7a283fabfb9","sha512_sri":"sha512-3jZEBRH5b5YeV3WUPFfT/vkikQmONpQfIKxGa3wR7cHw3k0Liow0FRDVEs56JXaDakfZICUVX9Ezt40E5LmaMA=="},"filename":"boxy-fixture-pfa-35.3.4.tgz"}],"evidence_files":[{"path":"_polyfill.js","sha256":"3b3661fb455d5fcf0ec76d1e6f6be3062f39a0dbbbe277621bf88550dbe572e3","tlsh":"53a186a506a6301847b0dbe1c7075415f55af6633780d184fb9c69981fb3224c3b2efc"},{"path":"lib/telemetry.js","sha256":"8644ced59ec7a435711e3f0e21b9d012ba3dc414ca667a0daa193e755a0afeb5","tlsh":"62835055566a242186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/boxy-fixture-pfa/MAL-2026-13047.json","cwes":[{"description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code","cweId":"CWE-506"}]}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}