Malicious code in bigops-api-customer (npm)
On require() of bigops-api-customer, index.js loads _compat.js which downloads an OS-specific native binary from obfuscated Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev) with a DNS-TXT fallback resolver under wel1.ru. Destination hostnames are assembled via array-join string splits (e.g. ["oo","b-worker.cf101-adf.workers",".de","v"].join("")) to defeat static matching. The fetched bytes are written to /tmp or %TEMP% under disguising names such as.cache_<hex> and dotnet_diag_<hex>.exe, chmod 0755, and executed detached via spawn("/bin/sh", ["-c", fp + " &"], {detached:true, stdio:"ignore"}).unref() (with a spawn("cmd") branch for Windows). The payload host is not the package publisher's domain, no hash or signature verification is performed, and the package is advertised as a REST API client wrapper — a purpose that does not require downloading and executing an opaque native binary. Additional cover-story features (DISABLE_TELEMETRY / ANALYTICS_OPT_OUT / DO_NOT_TRACK env checks, TTL rate-limit stamp file, randomized server ordering, "analytics"/"telemetry" comments) surround the dropper logic. Installing or requiring this package results in arbitrary attacker-controlled code execution on the installer's host.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
MAL-2026-12833 is recorded against 1 package.
Published on 5 August 2026 and last revised on 6 August 2026. No public exploit is currently recorded for this entry. Record sourced from OSV.
Details
Affected Packages
| Software | From version | Fixed in |
|---|---|---|
| bigops-api-customer | — | — |
References
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