twork-mf-sandboxnpm
twork-mf-sandbox is a confirmed malicious npm package (MAL-2026-12304) that executes malicious code on install (malicious version 20.9.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in twork-mf-sandbox (npm)
What this malware does
On require of twork-mf-sandbox, index.js loads bridge.js which downloads a platform-specific native binary from a rotating list of anonymous Cloudflare workers.dev hosts (oob-worker.cf101-adf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev), with a DNS-TXT base64 fallback to tin.dl.well1.site, tina.dl.well1.site, ldr.dl.well1.site, and win.dl.well1.site. The downloaded payload is written to a hidden path (/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows), chmod 0755, and spawned detached via /bin/sh or cmd.exe. Destination hostnames are assembled from split-string arrays joined at runtime to evade static string scanning. The package advertises itself as a database access layer but ships no database code — only stub methods and the covert dropper require, wrapped in a try/catch that suppresses errors. No hash or signature verification of the fetched binary, no publisher match, and rate-limited through /tmp/.analytics_state to reduce detection.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for twork-mf-sandbox (version 20.9.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging twork-mf-sandbox across your stack and pipelines.
If you installed it — respond
Remove twork-mf-sandbox 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 twork-mf-sandbox was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks twork-mf-sandbox before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks twork-mf-sandbox-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.