What does the devplatform-nx-svelte malware do?

On require of the package, _compat.js constructs C2 hostnames by joining split string fragments to evade static inspection, downloads a platform-specific executable from Cloudflare Workers subdomains (oob-worker.cf1**-***.workers.dev), and falls back to a DNS-TXT covert channel that reassembles base64 chunks from TXT records at c. .dl.wel1.ru / N. .dl.wel1.ru across sdk/ext/pkg/net.dl.wel1.ru. The retrieved bytes are written to a temp path with a disguised name (e.g. dotnet_diag_*.exe,.cache_*), chmodded 755 on Unix, and spawned detached via /bin/sh -c ' &' or cmd.exe /c start /b. Cover-story naming (markerPath 'analytics_state', a DISABLE_TELEMETRY opt-out, and a n

Which versions of devplatform-nx-svelte are malicious?

The following npm versions of devplatform-nx-svelte are flagged malicious: 35.6.8. Treat any of these as compromised.

How do I remediate devplatform-nx-svelte if I installed it?

devplatform-nx-svelte establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.

I already installed devplatform-nx-svelte — how do I know if it already compromised me?

If devplatform-nx-svelte 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-nx-svelte part of a known attack campaign?

Yes — devplatform-nx-svelte is associated with the IN-MAL-2026-015048 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-nx-svelte 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-nx-svelte (version 35.6.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging devplatform-nx-svelte across your stack and pipelines.

Malicious package

devplatform-nx-sveltenpm

devplatform-nx-svelte is a confirmed malicious npm package (MAL-2026-12729) that opens a backdoor for remote access (malicious version 35.6.8). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in devplatform-nx-svelte (npm)

MAL-2026-12729

Immediate action

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

npm uninstall devplatform-nx-svelte

What this malware does

On require of the package, compat.js constructs C2 hostnames by joining split string fragments to evade static inspection, downloads a platform-specific executable from Cloudflare Workers subdomains (oob-worker.cf1**-***.workers.dev), and falls back to a DNS-TXT covert channel that reassembles base64 chunks from TXT records at c.<subdomain>.dl.wel1.ru / N.<subdomain>.dl.wel1.ru across sdk/ext/pkg/net.dl.wel1.ru. The retrieved bytes are written to a temp path with a disguised name (e.g. dotnet_diag.exe,.cache_), chmodded 755 on Unix, and spawned detached via /bin/sh -c '<path> &' or cmd.exe /c start /b. Cover-story naming (markerPath 'analytics_state', a DISABLE_TELEMETRY opt-out, and a no-op _l logger) frames the dropper as telemetry. The fetch targets are not the package's publisher, the payload is opaque, and there is no integrity verification. The package name resembles legitimate Nx/Svelte tooling but the shipped code performs unauthenticated remote code execution on every installer that imports it.

Malicious versions

1 flagged

35.6.8

Indicators of compromise (SHA-256)

19a9e164d3a912ce2cb11abb935eb46fdfa9bb7ef12acbe4a305867cb8942306

Detection & response playbook

Backdoor / remote access

Find it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for devplatform-nx-svelte (version 35.6.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging devplatform-nx-svelte across your stack and pipelines.
If you installed it — respond
devplatform-nx-svelte establishes remote access, so treat any host that installed it as fully compromised. Isolate the machine, remove the package, rotate all credentials it could reach, and rebuild from a trusted image rather than cleaning in place — a backdoor may have planted additional persistence.
Did it already run?
If devplatform-nx-svelte 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-nx-svelte 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-nx-svelte on npm has been identified as a malicious package (version 35.6.8 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015048

References

npmjs.com

Credits

Amazon Inspector · finder

Detect & block this

O3 blocks devplatform-nx-svelte-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the C2 callback and severs the channel.

Malware detection Runtime egress monitoring

Explore

All malware advisories How O3 detects malware Vulnerability database