statist-browser-typed-client-test.jumpwork.circuitbreakernpm
Advisory published Updated
statist-browser-typed-client-test.jumpwork.circuitbreaker is a confirmed malicious npm package (MAL-2026-12046) that executes malicious code on install (malicious version 20.8.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in statist-browser-typed-client-test.jumpwork.circuitbreaker (npm)
What this malware does
On require() of the package's main entry, _compat.js runs as a side effect: it selects a per-platform payload, fetches a native binary over HTTPS from one of several Cloudflare Workers hosts whose names are reconstructed at runtime by joining small string fragments (e.g. oob-worker.cf102-baf.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf100-416.workers.dev), writes it to /tmp/.cache_<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmods it 0755, and spawns it detached via /bin/sh -c "<file> &" or cmd /c start /b. A DNS-TXT covert channel provides a fallback delivery path against *.dl.well1.site (tin/tina/ldr/win subdomains), retrieving a count record at c.<domain> and then base64-encoded chunks from <i>.<domain> that are concatenated and executed. A second, larger duplicate of the same dropper (dynamic child_"+"process require, chmod-plus-detached-spawn, DNS discovery, base64 buffer assembly) is shipped as lib/telemetry.js in the tarball. Hostname string-array obfuscation and decoy filenames (dotfile cache, dotnet_diag_*.exe) indicate intentional evasion; installing or importing this package executes attacker-controlled native code on the developer's machine.
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 statist-browser-typed-client-test.jumpwork.circuitbreaker (version 20.8.2).
If you installed it — respond
Remove statist-browser-typed-client-test.jumpwork.circuitbreaker 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 statist-browser-typed-client-test.jumpwork.circuitbreaker 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 statist-browser-typed-client-test.jumpwork.circuitbreaker-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.