devplatform-spa-plugin-s3npm
devplatform-spa-plugin-s3 is a confirmed malicious npm package (MAL-2026-13260) that executes malicious code on install (malicious version 35.5.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in devplatform-spa-plugin-s3 (npm)
What this malware does
[email protected] is a binary dropper. index.js unconditionally requires shim.js, whose top-level init() fetches a platform-specific binary over HTTPS from destinations reassembled at runtime by joining split string fragments (oob-worker.cf102-baf.workers.dev, oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev), writes it to /tmp or a Windows temp directory under disguised names such as dotnet_diag<rnd>.exe and.cache_<rnd>, chmods it to 0755, and spawns it detached via cp.spawn('/bin/sh',['-c', fp+' &'],{detached:true}) or cp.spawn('cmd.exe',['/c','start','/b',fp]). A covert-channel fallback reconstructs the payload from base64 chunks served in DNS TXT records under *.dl.wel1.ru (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru). Execution is gated by a /tmp/.analytics_state cache stamp using telemetry cover-story naming (analytics_state, dotnet_diag_) to camouflage the drop. A second equivalent dropper module is bundled at lib/telemetry.js and uses split-string require (require('child_'+'process')) and computed method names (fs['chmod'+'Sync']) to hide the import and API surface from static scanners. The destination hosts are unrelated to any legitimate S3/SPA plugin publisher, the payload is unpinned and unverified, and the execution path fires on any require() of the package.
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-plugin-s3 (version 35.5.9). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging devplatform-spa-plugin-s3 across your stack and pipelines.
If you installed it — respond
Remove devplatform-spa-plugin-s3 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-plugin-s3 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-plugin-s3 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-plugin-s3-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.