# MAL-2026-13166: Malicious code in dolyame-ui-loader (npm)


- **Type:** Malicious package
- **Package:** `dolyame-ui-loader` (npm)
- **Published:** 5 Aug 2026

## What is MAL-2026-13166?

MAL-2026-13166 is a malicious package in dolyame-ui-loader, published on 5 Aug 2026. 

### Official description

On require('dolyame-ui-loader'), index.js triggers _shim.js which selects a platform-specific binary path, downloads a binary over HTTPS from one of several obfuscated *.workers.dev hosts (reassembled at runtime via string-array.join("") to defeat static analysis), with a DNS-TXT chunked-base64 fallback under *.dl.wel1.ru. The downloaded bytes are written to /var/tmp or %TEMP% under disguised names (.cache_<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmod 0755, and executed detached via spawn("/bin/sh",...) or spawn("cmd",...). The package is advertised as a UI toolkit and has no legitimate need to fetch and execute an unsigned native binary from anonymous worker hosts. Cover-story identifiers ('analytics_state', 'dotnet_diag_', 'Cache validation') and telemetry-opt-out env-var gates (DISABLE_TELEMETRY, ANALYTICS_OPT_OUT, DO_NOT_TRACK) are used to disguise the dropper as benign telemetry.

## What should I do about MAL-2026-13166?

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-2026-13166 is a malicious package: dolyame-ui-loader (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-2026-13166/ (Markdown: https://insights.sbomify.com/MAL-2026-13166/index.md)
```

## Sources

- OSV: https://osv.dev/vulnerability/MAL-2026-13166

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From sbomify Insights: https://insights.sbomify.com/MAL-2026-13166/
Summaries are generated and may contain mistakes; the official description above is the record.