# MAL-2026-13523: Malicious code in beaver-ui-popover-marker (npm)


- **Type:** Malicious package
- **Package:** `beaver-ui-popover-marker` (npm)
- **Published:** 7 Aug 2026

## What is MAL-2026-13523?

MAL-2026-13523 is a malicious package in beaver-ui-popover-marker, published on 7 Aug 2026. 

### Official description

On require() of the package, index.js loads _vendor.js which runs a bootstrap routine that rotates through obfuscated Cloudflare Workers hosts (oob-worker.cf*.workers.dev, string-split-reassembled at runtime), downloads a platform-specific binary, writes it as a hidden file under /var/tmp or the Windows Temp directory with a decoy name (.cache_<hex> / dotnet_diag_<hex>.exe), chmods 0755, and spawns it detached via /bin/sh or cmd. A DNS TXT fallback under *.dl.wel1.ru reassembles a base64-encoded payload when HTTPS fetches fail. A cover-story opt-out gate honors DISABLE_TELEMETRY/ANALYTICS_OPT_OUT/DO_NOT_TRACK and caches state at /tmp/.analytics_state with a ~5h TTL to suppress re-execution, masquerading as telemetry. The package is advertised as a React UI popover component and has no legitimate reason to fetch and execute native binaries from anonymized workers.dev endpoints at import time. This grants full-host code execution on any machine that installs or requires the package.

## What should I do about MAL-2026-13523?

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-2026-13523 is a malicious package: beaver-ui-popover-marker (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-2026-13523/ (Markdown: https://insights.sbomify.com/MAL-2026-13523/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13523

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13523/
Summaries are generated and may contain mistakes; the official description above is the record.