{"id":"MAL-2026-12155","summary":"Malicious code in bigops-chat-files-hub-client (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (77deda11667a4ff5ed546ed7c8279d8cad81eb78b67d9e90208122522b8f681b)\nThe package's main entry index.js require()s./_shim, which on load fetches a platform-specific binary from obfuscated Cloudflare Workers hosts (oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev) with a *.dl.wel1.ru fallback, writes it to a temp path as dotnet_diag_\u003chex\u003e.exe or.cache_\u003chex\u003e, chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe /c start /b. Destination hostnames are reconstructed at runtime from split string fragments joined with.join(\"\") to hide them from static inspection. A second dropper module lib/telemetry.js (81 KB) ships in the tarball with the same base64-chunk decode + spawn + chmod 0755 mechanics wrapped in Sentry-like class names; it is not on the reachable require() graph in this version but is present for future activation. Telemetry-themed filenames and opt-out env vars (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK) provide cover. The stated purpose (chat files hub client) has no legitimate need to fetch and execute native binaries from anonymous edge-worker hosts.\n","modified":"2026-08-05T10:05:55.687254877Z","published":"2026-08-05T08:45:09Z","database_specific":{"malicious-packages-origins":[{"versions":["35.4.6"],"id":"IN-MAL-2026-014402","import_time":"2026-08-05T09:28:06.747213813Z","modified_time":"2026-08-05T08:45:09Z","sha256":"77deda11667a4ff5ed546ed7c8279d8cad81eb78b67d9e90208122522b8f681b","source":"amazon-inspector"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/bigops-chat-files-hub-client/v/35.4.6"}],"affected":[{"package":{"name":"bigops-chat-files-hub-client","ecosystem":"npm","purl":"pkg:npm/bigops-chat-files-hub-client"},"versions":["35.4.6"],"database_specific":{"cwes":[{"name":"Embedded Malicious Code","cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature."}],"indicators":{"evidence_files":[{"path":"_shim.js","sha256":"7e62d09ed5bf383f9df485bcff090729f11d5e7b2754ef885668629b9190f70c","tlsh":"79b197aa016670184770dbe4c7175415f65bf66373809294fb9ca5881fb2224c3b3efc"},{"sha256":"947f074127d6d5b1e888800fe84b044836e4b6690050e5a41db56088b4470ebf","tlsh":"1c835055566a242186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc","path":"lib/telemetry.js"}],"package_integrity":[{"filename":"bigops-chat-files-hub-client-35.4.6.tgz","hashes":{"sha512_sri":"sha512-goR6I+ZQnTB3nqmGRPpJW5Kdio+UmNHlP4kq6N2hZsBJ65G9IrMdzO7dWOblGWhw76GDt5aHvGBEeyHh+ot17g==","sha1":"a73b87a5c2d1e9b7eee0867d38d3ac1f8d9a41ac"}}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-chat-files-hub-client/MAL-2026-12155.json"}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}