bigops-opening-file-handler

{"modified":"2026-08-05T15:37:01Z","published":"2026-08-05T15:37:01Z","schema_version":"1.7.4","id":"MAL-2026-13229","summary":"Malicious code in bigops-opening-file-handler (npm)","details":"\n---\n_-= Per source details. Do not edit below this line.=-_\n\n## Source: amazon-inspector (9c423840bea5711af66c8f9c24eca1c406a4fa929dc6b9e9d947ec71ea5adc39)\nOn require of bigops-opening-file-handler, index.js loads _support.js which selects a platform-specific asset (linux/darwin/win32) and downloads an opaque native binary from one of four hardcoded Cloudflare Workers subdomains (oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev), with a DNS-TXT discovery fallback under *.dl.wel1.ru (e.g. sdk.dl.wel1.ru). The hostnames are reassembled at runtime from string arrays via.join('') to evade static matching. The fetched bytes are written to /var/tmp or %TEMP% under disguised names such as.cache_<hex> or dotnet_diag_<hex>.exe, chmodded 0755, and spawned detached via /bin/sh -c or cmd. The package advertises itself as a file-handler abstraction; the delivered payload is unrelated native code from author-controlled infrastructure, executed automatically when the module is required.\n","affected":[{"package":{"ecosystem":"npm","name":"bigops-opening-file-handler"},"versions":["35.9.2"],"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":"_support.js","sha256":"e493e0d9ef8be2aa73b7bbc3cfc455833b14d698185fb57b3488952a2f0da170","tlsh":"9bb1765a16a670184f70e7e4c61b4816f66bf6633680c2c4fb9ca5945f7352882b2efc"}],"package_integrity":[{"filename":"bigops-opening-file-handler-35.9.2.tgz","hashes":{"sha1":"f21da25e4bcdf29428eed451a402d6f8236f620a","sha512_sri":"sha512-FAufdbwSiu4n8T7gTgkk7n0ACacR2FEsnBzGVz+5R2rC2cvyMKHOG75ZYpFga5P2PbHt+8BV92090sWbRAkvqw=="}}]}}}],"references":[{"type":"PACKAGE","url":"https://www.npmjs.com/package/bigops-opening-file-handler/v/35.9.2"}],"credits":[{"name":"Amazon Inspector","type":"FINDER","contact":["inspector-research@amazon.com"]}],"database_specific":{"malicious-packages-origins":[{"id":"IN-MAL-2026-015767","import_time":"2026-08-05T16:13:42.924541564Z","modified_time":"2026-08-05T15:37:01Z","sha256":"9c423840bea5711af66c8f9c24eca1c406a4fa929dc6b9e9d947ec71ea5adc39","source":"amazon-inspector","versions":["35.9.2"]}]}}