MAL-2026-13048 Malicious code in boxy-fixture-sb (npm)
Malicious package
Published
MAL-2026-13048 is a malicious package: boxy-fixture-sb (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-2026-13048/ (Markdown: https://insights.sbomify.com/MAL-2026-13048/index.md)
- Package
- boxy-fixture-sb
- Registry
- npm
What is MAL-2026-13048?
MAL-2026-13048 is a malicious package in boxy-fixture-sb, published on 5 Aug 2026.
Official description
On require() of boxy-fixture-sb, index.js loads compat.js which reconstructs Cloudflare Workers hostnames from string-split arrays (joined at runtime to form oob-worker.cf*.workers.dev), downloads a platform-specific binary via https.get, writes it to /tmp or %TEMP% under cover-story names such as.cache<hex> and dotnet_diag_<hex>.exe, chmods 0755, and spawns it detached via /bin/sh -c "<path> &" or cmd.exe /c start. A DNS-TXT fallback channel reads base64 payload chunks from c.<domain>/<i>.<domain> under *.dl.wel1.ru. Cover-story identifiers (analytics_state, DISABLE_TELEMETRY) and hostname obfuscation confirm evasion intent. The package name suggests a test fixture but its only observed effect at import is fetching and executing an opaque remote payload on the installer's machine.
What should I do about MAL-2026-13048?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.