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

Malicious package Published
Package
beaver-ui-popover-marker
Registry
npm

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.

Sources

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