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 installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

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?

Search your lockfiles and build artifacts for devplatform-nx-svelte (version 35.6.8).

Malicious package

devplatform-nx-sveltenpm

Advisory published Aug 5, 2026Updated Aug 5, 2026

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
Search your lockfiles and build artifacts for devplatform-nx-svelte (version 35.6.8).
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 installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.

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

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