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Malicious package

devplatform-cli-plugin-testnpm

Advisory published Updated

devplatform-cli-plugin-test is a confirmed malicious npm package (MAL-2026-12703) that opens a backdoor for remote access (malicious version 35.4.5). Do not install it — remove it immediately and rotate any exposed credentials.

Malicious code in devplatform-cli-plugin-test (npm)

MAL-2026-12703
Immediate action
Remove the package, then rotate any secrets the build/runtime could reach.
npm uninstall devplatform-cli-plugin-test

What this malware does

On require(), runtime.js selects a platform-specific asset, downloads a binary over https.get from hardcoded Cloudflare Workers hosts (with a DNS TXT base64 fallback under dl.wel1.ru), writes it to /var/tmp or %TEMP% under names mimicking diagnostic tools (dotnet_diag.exe,.cache_,.analytics_state), chmods it 0o755, and spawns it detached via spawn('/bin/sh', ['-c', fp+' &'], {detached:true}) or cmd.exe /c start /b. C2 hostnames and fallback domains are reconstructed at runtime from split-string arrays to evade static scanners. No hash or signature verification. The destinations are non-publisher, mutable, and disguised, and the package advertises itself as test fixtures while performing this drop-and-execute on load.

Malicious versions

1 flagged
35.4.5

Indicators of compromise (SHA-256)

307cdf72132de0cbce8bbbe7fd65b7c89d9c879fd917ff6a9e06e41ff56d299e

Detection & response playbook

Backdoor / remote access

  1. Find it

    Search your lockfiles and build artifacts for devplatform-cli-plugin-test (version 35.4.5).

  2. If you installed it — respond

    devplatform-cli-plugin-test 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.

  3. Did it already run?

    If devplatform-cli-plugin-test 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-cli-plugin-test on npm has been identified as a malicious package (version 35.4.5 flagged). It should be removed immediately — do not install or keep it in your dependency tree.

Campaign

IN-MAL-2026-015074

References

Credits

  • Amazon Inspector · finder

Detect & block this

O3 blocks devplatform-cli-plugin-test-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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devplatform-cli-plugin-test (npm) malicious package — MAL-2026-12703 | O3 Security