{"id":"MAL-2026-13248","summary":"Malicious code in bigops-rx-post-message (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (1298706de8e41561be6743e6d8349c5feefb81bec1ba71f3f2da3995d845ac98)\nOn require() of bigops-rx-post-message, index.js executes _init.js at module top level, which downloads a platform-specific binary from Cloudflare Workers hosts whose names are assembled at runtime from string-split arrays (e.g. oob-worker.cf10x-*.workers.dev) with a DNS-TXT base64 fallback across sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written under /var/tmp or %TEMP% with a disguised name (.cache_\u003chex\u003e / dotnet_diag_\u003chex\u003e.exe), chmodded 0755, and spawn-detached via /bin/sh -c or cmd.exe. No hash or signature verification is performed, the destinations are not the publisher's infrastructure, and lib/telemetry.js contains the same dropper primitives with `child_process` obtained via string concatenation (require(\"child_\"+\"process\")) and fs[\"chmod\"+\"Sync\"] indexed by string to evade static scanners. Installing or requiring this package causes an unpinned, attacker-controlled executable to run on the installer's host.\n","modified":"2026-08-05T16:50:12.086426680Z","published":"2026-08-05T15:33:54Z","database_specific":{"malicious-packages-origins":[{"sha256":"1298706de8e41561be6743e6d8349c5feefb81bec1ba71f3f2da3995d845ac98","source":"amazon-inspector","versions":["35.1.5"],"id":"IN-MAL-2026-015747","import_time":"2026-08-05T16:13:39.744159159Z","modified_time":"2026-08-05T15:33:54Z"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/bigops-rx-post-message/v/35.1.5"}],"affected":[{"package":{"name":"bigops-rx-post-message","ecosystem":"npm","purl":"pkg:npm/bigops-rx-post-message"},"versions":["35.1.5"],"database_specific":{"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-rx-post-message/MAL-2026-13248.json","cwes":[{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."}],"indicators":{"package_integrity":[{"filename":"bigops-rx-post-message-35.1.5.tgz","hashes":{"sha512_sri":"sha512-nfToO+N5uTG+p/QrNOwoOqFAtSaKQx8cpb1P9AGCsYgCbP8zKpJyho/FEXOTcTYBhQOeZKnOnbwgJ70RGpxMLQ==","sha1":"0f1bf92c48021ecfa7114dd98a1f906431f7989c"}}],"evidence_files":[{"path":"_init.js","sha256":"b9ada96ecd1b232a0ab10ccb69cd3c523addb3ed4940b812724c09314624a7cd","tlsh":"a9a1a85a15a970184bb0a7e0c7174419f65bf653378086d5f75c55981fb21248372efc"}]}}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}