# MAL-2026-12556: Malicious code in checkout-desktop-input-card (npm)


- **Type:** Malicious package
- **Package:** `checkout-desktop-input-card` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12556?

MAL-2026-12556 is a malicious package in checkout-desktop-input-card, published on 5 Aug 2026. 

### Official description

On require of this package, index.js loads _runtime.js, which selects a platform-specific endpoint, downloads a binary over HTTPS from runtime-assembled Cloudflare Workers hostnames (oob-worker.cf102-baf.workers.dev and siblings cf100-416, cf103-070) with a DNS-TXT base64 fallback across sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched bytes are written to /var/tmp or %TEMP% under masquerading names (dotnet_diag_*.exe,.cache_*), chmodded 0755 on POSIX, and spawned detached via /bin/sh -c or cmd.exe. Destination hostnames are split across arrays and reassembled with.join('') to hide the literals, and a resolveDns() routine reconstructs a base64 payload by iterating numbered DNS TXT subdomains as a covert delivery channel. A TTL stamp guards against re-execution. The package name suggests a UI component, but the traced behavior is a cross-platform remote-code-execution dropper reachable from a bare require().

## What should I do about MAL-2026-12556?

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-2026-12556 is a malicious package: checkout-desktop-input-card (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-2026-12556/ (Markdown: https://insights.sbomify.com/MAL-2026-12556/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12556

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12556/
Summaries are generated and may contain mistakes; the official description above is the record.