{"id":"MAL-2026-12853","summary":"Malicious code in bigops-utils (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (36dcb322eace39209bb0092ab7ea7c658481887a48eff948f116bfb7909ec131)\nLoading the package's main entry point auto-invokes _helpers.js init(), which downloads an OS-specific binary from obfuscated Cloudflare Workers subdomains (hostnames assembled at runtime from split-string arrays such as _MIRRORS=['oob-worker.cf102-baf.w','orke','rs.','de','v'].join('')) with a DNS-TXT chunked fallback that reassembles base64 chunks from TXT records under *.dl.wel1.ru. The fetched bytes are written to /tmp or %TEMP% under deceptive names ('.cache_\u003crand\u003e', 'dotnet_diag_\u003crand\u003e.exe'), chmod'd 0755, and detached-spawned via spawn('/bin/sh', ['-c', fp+' &'], {detached:true}) or cmd.exe /c start /b. No hash or signature verification is performed and the destinations are not tied to any advertised publisher. Sibling lib/telemetry.js uses dynamic API construction (require('child_'+'process'), fs['chmod'+'Sync']) to further evade static analysis. The behavior is framed as 'analytics/telemetry' but is an import-time remote-code dropper.\n","modified":"2026-08-05T15:50:18.239968494Z","published":"2026-08-05T14:59:18Z","database_specific":{"malicious-packages-origins":[{"versions":["35.4.8"],"id":"IN-MAL-2026-015523","import_time":"2026-08-05T15:19:56.011535528Z","modified_time":"2026-08-05T14:59:18Z","sha256":"36dcb322eace39209bb0092ab7ea7c658481887a48eff948f116bfb7909ec131","source":"amazon-inspector"}]},"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/bigops-utils/v/35.4.8"}],"affected":[{"package":{"name":"bigops-utils","ecosystem":"npm","purl":"pkg:npm/bigops-utils"},"versions":["35.4.8"],"database_specific":{"indicators":{"evidence_files":[{"sha256":"1a8da11952bcec274c2fd7cc9ae8dfdb8e3ab2ae48bc5b42a06ea9cc62261903","tlsh":"49b1986a156670184bb0d7e4c7176415f65ae5637380c2a4fb9ca9d81fb312483b3efc","path":"_helpers.js"}],"package_integrity":[{"hashes":{"sha1":"b222b6c71700676b311eff358b2cfd2f2cb4208a","sha512_sri":"sha512-j00jKChS6tLfhTp062RagJh2pGKBnH9jjvWAwWyh9P+L2MxNC9s4aXsip+AutpKle5uwz4ISbCS8Hz6Tjn1Rhg=="},"filename":"bigops-utils-35.4.8.tgz"}]},"source":"https://github.com/ossf/malicious-packages/blob/main/osv/malicious/npm/bigops-utils/MAL-2026-12853.json","cwes":[{"cweId":"CWE-506","description":"The product contains code that appears to be malicious in nature.","name":"Embedded Malicious Code"}]}}],"schema_version":"1.8.0","credits":[{"name":"Amazon Inspector","contact":["inspector-research@amazon.com"],"type":"FINDER"}]}