MAL-2026-13013 Malicious code in bnpl-blocks-post-css (npm)
Malicious package
Published
MAL-2026-13013 is a malicious package: bnpl-blocks-post-css (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-2026-13013/ (Markdown: https://insights.sbomify.com/MAL-2026-13013/index.md)
- Package
- bnpl-blocks-post-css
- Registry
- npm
What is MAL-2026-13013?
MAL-2026-13013 is a malicious package in bnpl-blocks-post-css, published on 5 Aug 2026.
Official description
On require(), polyfill.js reconstructs attacker-controlled hostnames from string-split fragments (oob-worker.cf103-070.workers.dev, with a DNS-TXT fallback via sdk.dl.wel1.ru), downloads a platform-specific native binary, writes it to /tmp or %TEMP% under a disguised name (.cache<hex> on Unix, dotnet_diag_<hex>.exe on Windows), chmods it 0o755, and spawns it detached via spawn('/bin/sh', ['-c', <path> + ' &'], {detached:true}) or the cmd equivalent. lib/telemetry.js contains a second implementation of the same fetch->write->chmod 755->spawn pattern with a base64-decoded payload under an analytics-SDK cover story. The package is advertised as a CSS-blocks utility and has no legitimate reason to fetch and execute native binaries; the string-split obfuscation of the download hosts and the 'analytics_state' / DISABLE_TELEMETRY cover-story naming further confirm hostile intent.
What should I do about MAL-2026-13013?
Remove the package from your dependencies and lockfiles, then rotate any secrets on machines where it was installed.