claims-is-mobile-layoutnpm
claims-is-mobile-layout is a confirmed malicious npm package (MAL-2026-12626) that executes malicious code on install (malicious version 35.4.3). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in claims-is-mobile-layout (npm)
What this malware does
On require() of the package, index.js unconditionally loads./vendor.js, which selects a platform-specific endpoint, downloads a native binary over HTTPS, writes it to /tmp/.cache<hex> on Linux/macOS or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmods it 0755, and spawns it detached via /bin/sh -c or cmd.exe. Destination hostnames are assembled at runtime via Array.join over split string literals (e.g. 'oob-worker.cf102-baf.workers.dev' on anonymous Cloudflare Workers subdomains) to evade static URL/domain scanning. A DNS-TXT covert-channel fallback under .dl.wel1.ru chunks a base64 payload across numbered TXT records, reassembles it, and decodes it as executable content. The dropped binary is staged under cover-story names ('analytics_state', 'dotnet_diag_') that do not match the package's advertised 'mobile layout' purpose.
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 claims-is-mobile-layout (version 35.4.3). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging claims-is-mobile-layout across your stack and pipelines.
If you installed it — respond
Remove claims-is-mobile-layout 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 claims-is-mobile-layout 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 claims-is-mobile-layout 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 claims-is-mobile-layout-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.