devplatform-spa-clinpm
devplatform-spa-cli is a confirmed malicious npm package (MAL-2026-12755) that executes malicious code on install (malicious version 35.9.2). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in devplatform-spa-cli (npm)
What this malware does
index.js requires./polyfill on module load, which asynchronously fetches a platform-selected binary from runtime-assembled Cloudflare Workers subdomains (oob-worker.cf100-*.workers.dev / cf101/cf102/cf103 variants) with a DNS TXT chunked-base64 fallback via *.dl.wel1.ru. The payload is written under /var/tmp or %TEMP% with a cover-story name (.cache<hex> on POSIX, dotnet_diag_<hex>.exe on Windows), chmod 0o755, and detach-spawned via /bin/sh -c "<file> &" or cmd.exe /c start /b. Destination hostnames and the child_process require are assembled by array-join string concatenation to evade static inspection. A second implementation of the same drop-and-exec chain (endpoint rotation, DNS TXT failover, chmod 0755, /bin/sh spawn) is present in lib/telemetry.js. There is no hash or signature verification, the hosts are anonymous mutable Cloudflare Workers unrelated to any declared publisher, and execution occurs automatically when the module is required.
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
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for devplatform-spa-cli (version 35.9.2). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging devplatform-spa-cli across your stack and pipelines.
If you installed it — respond
Remove devplatform-spa-cli 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 devplatform-spa-cli 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 devplatform-spa-cli 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 devplatform-spa-cli-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.