Which versions of devplatform-s3-uploader are malicious?

The following npm versions of devplatform-s3-uploader are flagged malicious: 35.4.4. Treat any of these as compromised.

How do I remediate devplatform-s3-uploader if I installed it?

Remove devplatform-s3-uploader 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.

I already installed devplatform-s3-uploader — how do I know if it already compromised me?

If devplatform-s3-uploader 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.

Is devplatform-s3-uploader part of a known attack campaign?

Yes — devplatform-s3-uploader is associated with the IN-MAL-2026-015018 campaign. Packages in the same campaign often share infrastructure and payloads, so check whether any related packages are also in your dependency tree.

How do I find devplatform-s3-uploader across my projects, lockfiles, and CI pipelines?

Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for devplatform-s3-uploader (version 35.4.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging devplatform-s3-uploader across your stack and pipelines.

Malicious package

devplatform-s3-uploadernpm

devplatform-s3-uploader is a confirmed malicious npm package (MAL-2026-12749) that executes malicious code on install (malicious version 35.4.4). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in devplatform-s3-uploader (npm)

MAL-2026-12749

Immediate action

Remove the package, then rotate any secrets the build/runtime could reach.

npm uninstall devplatform-s3-uploader

What this malware does

On require() of the package, index.js loads helpers.js which unconditionally runs a start() routine that selects a platform-specific asset path, fetches an opaque native binary from one of four hardcoded Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, cf100-416.workers.dev, cf101-adf.workers.dev, cf102-baf.workers.dev), with a DNS-TXT fallback that reassembles base64 chunks from sdk.dl.wel1.ru / ext.dl.wel1.ru / pkg.dl.wel1.ru / net.dl.wel1.ru. The fetched bytes are written to a temp path under a cover-story name (e.g. dotnet-diag under /var/tmp or TEMP), chmod 0755, then executed detached via spawn('/bin/sh', ['-c', path + ' &']) or spawn('cmd',...) on Windows. No hash or signature verification. Network destinations are not the package publisher and are unrelated to the advertised 'S3 uploader' purpose. Host names and API identifiers are constructed by string-split/array-join (e.g. ['oob-worker.cf100-416.workers.','de','v'].join(''), require('child' + 'process'), fs['chmod' + 'Sync']) to evade static analysis. A secondary module lib/telemetry.js, presented as an 'analytics SDK', ships parallel dropper primitives (base64 chunk reassembly, bracket-obfuscated chmod to 0755, cp.spawn('/bin/sh', ['-c', filePath + ' &'], {detached:true})) — co-shipped fallback attack infrastructure.

Malicious versions

1 flagged

35.4.4

Indicators of compromise (SHA-256)

202bd53eb339cdbd72320893af375903622c29dc8f55c54c6dc9ae94d2e727b9

Detection & response playbook

Malicious package

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for devplatform-s3-uploader (version 35.4.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging devplatform-s3-uploader across your stack and pipelines.
If you installed it — respond
Remove devplatform-s3-uploader 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-s3-uploader 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-s3-uploader 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

No. devplatform-s3-uploader on npm has been identified as a malicious package (version 35.4.4 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015018

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks devplatform-s3-uploader-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.

Malware detection Runtime egress monitoring

Explore

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