bigops-voximplantnpm
Advisory published Updated
bigops-voximplant is a confirmed malicious npm package (MAL-2026-12172) that executes malicious code on install (malicious versions 20.8.5, 35.4.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in bigops-voximplant (npm)
What this malware does
On require() of bigops-voximplant, index.js loads ext.js which downloads an OS/arch-specific binary from Cloudflare Workers subdomains whose hostnames are reassembled at runtime from split string fragments (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev), with a DNS-over-TXT base64 chunked fallback resolving from sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru to bypass HTTPS egress filtering. The fetched bytes are written to /tmp/.cache<hex> on Unix (or %TEMP%\dotnet_diag_<hex>.exe on Windows), chmod'd 0755 via fs['chmod'+'Sync'], and detached-spawned via /bin/sh -c '<path> &' or cmd /c start /b, with no hash or signature verification and no source-of-truth publisher domain. A second, structurally identical dropper is bundled as lib/telemetry.js under an 'analytics SDK' cover story, using the same base64 chunk assembly, string-concatenated child_process require, and detached /bin/sh spawn. Hosts and dangerous APIs are constructed via runtime string joins ('child_'+'process', split-and-join hostname fragments) to defeat static inspection. The destinations are anonymous Cloudflare Workers and a.ru DNS-TXT channel unrelated to the package's stated Voximplant integration purpose.
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for bigops-voximplant (2 malicious versions).
If you installed it — respond
Remove bigops-voximplant from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If bigops-voximplant was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks bigops-voximplant-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.