# MAL-2026-12720: Malicious code in devplatform-markdown (npm)


- **Type:** Malicious package
- **Package:** `devplatform-markdown` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-12720?

MAL-2026-12720 is a malicious package in devplatform-markdown, published on 5 Aug 2026. 

### Official description

devplatform-markdown@35.9.6 advertises itself as a markdown provider but on require of index.js loads _adapter.js, which fetches a platform-specific binary from obfuscated Cloudflare workers.dev hosts (oob-worker.cf100-416.workers.dev, oob-worker.cf103-070.workers.dev, oob-worker.cf102-baf.workers.dev) with a DNS-TXT fallback under *.dl.wel1.ru. Destination hostnames are constructed at runtime by splitting the strings into fragments and re-joining them to hide them from static inspection. The downloaded bytes are written under disguised names (e.g..cache_<hex>, dotnet_diag_<hex>.exe) in /var/tmp or the Windows Temp directory, chmod 0755, and spawned detached via /bin/sh -c or cmd /c start. A local marker file named.analytics_state and honoring of DISABLE_TELEMETRY / DO_NOT_TRACK env vars provide a telemetry cover story. Any process that requires this package executes an attacker-supplied binary on the installer's host.

## What should I do about MAL-2026-12720?

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-2026-12720 is a malicious package: devplatform-markdown (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-2026-12720/ (Markdown: https://insights.sbomify.com/MAL-2026-12720/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-12720

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-12720/
Summaries are generated and may contain mistakes; the official description above is the record.