beaver-ui-popover-markernpm
beaver-ui-popover-marker is a confirmed malicious npm package (MAL-2026-13523) that executes malicious code on install (malicious version 35.5.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in beaver-ui-popover-marker (npm)
What this malware does
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.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for beaver-ui-popover-marker (version 35.5.8). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging beaver-ui-popover-marker across your stack and pipelines.
If you installed it — respond
Remove beaver-ui-popover-marker from your project and lockfile, then assume any secrets accessible to the build or runtime were exposed: rotate API keys, tokens, and credentials, and audit for unexpected outbound activity or persistence.
Did it already run?
If beaver-ui-popover-marker was ever installed, its post-install/runtime payload may have already executed. O3's L7 egress monitoring and runtime eBPF sensors detect the credential exfiltration or command-and-control callback after install and block the malicious outbound channel, so you catch and contain the actual compromise — not just the presence of the package.
How O3 protects you
O3 blocks beaver-ui-popover-marker before install through its supply-chain scanner, and if it has already run, detects and severs the exfiltration or C2 callback at runtime through L7 egress monitoring and eBPF.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks beaver-ui-popover-marker-class packages before install and in CI — and if it already ran, its runtime egress monitoring catches the malicious outbound activity and severs the channel.