{"schema_version":"1.8.0","id":"MAL-2026-12035","published":"2026-08-05T01:31:03Z","modified":"2026-08-05T01:49:47.486261513Z","summary":"Malicious code in bigops-auth-utils (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (ba54cfc2b542b8e388d852b80c0f409b2987423285eb6518d6dbc668e4c1a372)\nbigops-auth-utils@35.4.5 executes an install-time binary dropper on any require/import of the package. index.js top-level runs require('./setup'), which selects an OS/arch-specific asset path and downloads a binary over HTTPS from one of three string-split-obfuscated Cloudflare Workers hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev) with a DNS-TXT covert-channel fallback that reassembles base64-encoded chunks from sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched bytes are written to /var/tmp or %TEMP% under a disguising name (.cache_<hex> on POSIX, dotnet_diag_<hex>.exe on Windows), chmod 0755, and spawned detached via /bin/sh -c... & or cmd.exe /c start /b. A TTL marker suppresses re-execution and env-var opt-out flags are named to resemble telemetry toggles. A second copy of the same drop-and-spawn logic is duplicated inside lib/telemetry.js framed as an 'Analytics SDK', with require(\"child_\" + \"process\"), fs[\"chmod\" + \"Sync\"], and cp.spawn('/bin/sh', ['-c', filePath + ' &']) using string concatenation to evade static matching. Host construction via array-join splitting, cover-story framing, telemetry-shaped opt-out names, DNS covert-channel fallback, and duplicated execution paths are all evasion signals characteristic of a supply-chain dropper, not a build helper.\n","affected":[{"package":{"name":"bigops-auth-utils","ecosystem":"npm","purl":"pkg:npm/bigops-auth-utils"},"versions":["35.4.5"],"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":"setup.js","sha256":"c09efc54d5929254408ac006e3dee64069f3fccd28b4ff713bbfeabeaa1e4192","tlsh":"4da1975a166ab0188bb0ebe4c71b8815f55af6633780c294f79c69885fb3114c371efc"},{"path":"lib/telemetry.js","sha256":"b1197b0c8bcf9ee3da662daf24defcb3e3c486fad3dcb59d28dbb7736b2e580b","tlsh":"29835056566a102186b2b368df234107ff3685272643429dbafc82dc1fbd72092a5ffc"}],"package_integrity":[{"filename":"bigops-auth-utils-35.4.5.tgz","hashes":{"sha1":"42ad82d1832d117c9964b711b631e6e7dd980a12","sha512_sri":"sha512-j9uWq7vZUi80e4ru66YZMm6iPRGy0zbudGXj9GwOro698abs31IE/qn+soxzCa+egQoTsyT0VqivG0ODczfDOg=="}}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-auth-utils/MAL-2026-12035.json"}}],"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/bigops-auth-utils/v/35.4.5"}],"database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-011498","import_time":"2026-08-05T01:39:31.728580563Z","modified_time":"2026-08-05T01:31:03Z","sha256":"ba54cfc2b542b8e388d852b80c0f409b2987423285eb6518d6dbc668e4c1a372","source":"amazon-inspector","versions":["35.4.5"]}]},"credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}