{"id":"MAL-2026-12665","summary":"Malicious code in contract-contract-builder (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (3758ab87194c554acffc80e8cd2caf8fa8890e92854115edab08615877f22b5f)\nOn require() of the package, _platform.js downloads a platform-specific binary from Cloudflare Workers hosts whose names are assembled at runtime from split string fragments (oob-worker.cf100-416.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf102-baf.workers.dev). The fetched bytes are written to /tmp or %TEMP% under disguising names (.cache_\u003chex\u003e on POSIX, dotnet_diag_\u003chex\u003e.exe on Windows), chmodded 0755, and spawned detached via cp.spawn(\"/bin/sh\", [\"-c\", fp+\" &\"], {detached:true}) or the Windows equivalent. A DNS-TXT fallback channel under *.dl.wel1.ru reassembles a base64 payload from numbered TXT records (c.\u003cdomain\u003e, 0.\u003cdomain\u003e, 1.\u003cdomain\u003e,...) when HTTPS delivery fails. The package advertises itself as a UI toolkit; the fetched binary is unrelated to that purpose, unpinned, unverified, and executed on import.\n","modified":"2026-08-05T14:36:14.656032933Z","published":"2026-08-05T13:58:51Z","database_specific":{"malicious-packages-origins":[{"versions":["35.5.2"],"id":"IN-MAL-2026-015117","import_time":"2026-08-05T14:20:03.835543125Z","modified_time":"2026-08-05T13:58:51Z","sha256":"3758ab87194c554acffc80e8cd2caf8fa8890e92854115edab08615877f22b5f","source":"amazon-inspector"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/contract-contract-builder/v/35.5.2"}],"affected":[{"package":{"name":"contract-contract-builder","ecosystem":"npm","purl":"pkg:npm/contract-contract-builder"},"versions":["35.5.2"],"database_specific":{"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/contract-contract-builder/MAL-2026-12665.json","cwes":[{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."}],"indicators":{"evidence_files":[{"path":"_platform.js","sha256":"847545fac36267fd125c40480b2bbfc75cb83ac391fd85515ede82446c865fee","tlsh":"06a1856a11a570188bb0dbe1c2176416f66bf6632281c5d4f69c69d80ff622483b3efc"}],"package_integrity":[{"filename":"contract-contract-builder-35.5.2.tgz","hashes":{"sha1":"85b17bb10fa7f3776ca6a5e794645f9ff4a5dd6c","sha512_sri":"sha512-s+TL/tIAm+JiI4m5169sgfVWQBlrQWjJhOYyiEFo4WQNmrEGAENsQWEJAbD/d23P3gjO4R33D3E3ju2sXIXlow=="}}]}}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}