# MAL-2026-12601: Malicious code in checkout-use-disable-interaction (npm)


- **Type:** Malicious package
- **Package:** `checkout-use-disable-interaction` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12601?

MAL-2026-12601 is a malicious package in checkout-use-disable-interaction, published on 5 Aug 2026. 

### Official description

On require() of checkout-use-disable-interaction, index.js loads _vendor.js which downloads a platform-specific native binary from Cloudflare Workers subdomains under oob-worker.cf*.workers.dev, with a DNS TXT-record fallback channel at c.<domain> and 0.<domain>..N.<domain> under *.dl.wel1.ru whose base64-decoded fragments are concatenated into the same executable payload. Destination hostnames are assembled at runtime by string-splitting and array-join to evade static analysis. The payload is written to /var/tmp/.cache_<uid> on Linux/macOS or %TEMP%\dotnet_diag_<uid>.exe on Windows — cover-story filenames designed to blend with system artifacts — then chmod 0755 and spawned detached via /bin/sh -c '<path> &' or cmd /c start /b. A /tmp/.analytics_state (or %TEMP%\analytics_state) marker file is written and its mtime used as a ~6h re-run gate so the dropper re-fires periodically whenever any consumer imports the package. The package README advertises a benign microservice module; the shipped code does not match that purpose.

## What should I do about MAL-2026-12601?

Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.

## Fix prompt for AI coding agents

```text
MAL-2026-12601 is a malicious package: checkout-use-disable-interaction (npm). Every version was published to cause harm.

Task:
1. Search this repository's dependency manifests and lockfiles for the package, including transitive dependencies.
2. If it is present, remove it, regenerate the lockfile with the project's package manager, and replace whatever it was used for.
3. List any CI runners, developer machines or containers that installed it, so their secrets can be rotated.
4. If the package is not used anywhere, say so and change nothing.

Reference: https://insights.sbomify.com/MAL-2026-12601/ (Markdown: https://insights.sbomify.com/MAL-2026-12601/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12601

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12601/
Summaries are generated and may contain mistakes; the official description above is the record.