checkout-mobile-legalnpm
checkout-mobile-legal is a confirmed malicious npm package (MAL-2026-12577) that executes malicious code on install (malicious version 35.8.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-mobile-legal (npm)
What this malware does
On any require/import of this package, index.js loads init.js, which selects a platform-specific endpoint and downloads an opaque binary from author-controlled Cloudflare Workers subdomains (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev). The hostnames are assembled at runtime by joining string fragments (e.g., ["oob-worker.cf100-416",".work","ers.","dev"].join("")) to evade static inspection. The fetched bytes are written to /var/tmp (or %TEMP%) under disguised names (dotnet_diag<uid>.exe on Windows,.cache_<uid> on POSIX), chmodded 0755, and executed detached via cp.spawn("/bin/sh", ["-c",...]) or cmd.exe with no hash, signature, or publisher verification. A DNS-TXT fallback under *.dl.wel1.ru subdomains (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) reassembles a base64-encoded payload from TXT records and executes it when HTTPS retrieval fails, a covert channel intended to bypass egress HTTP filtering. A marker file.analytics_state and cover-story naming ("analytics SDK", dotnet_diag) present the code as telemetry, but the behavior is an unverified remote-code-execution dropper. Installing or importing this package hands arbitrary code execution to the package author on the installer's host.
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 checkout-mobile-legal (version 35.8.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-mobile-legal across your stack and pipelines.
If you installed it — respond
Remove checkout-mobile-legal 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 checkout-mobile-legal 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 checkout-mobile-legal 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 checkout-mobile-legal-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.