tui-react-mobile-stylesnpm
tui-react-mobile-styles is a confirmed malicious npm package (MAL-2026-12053) that executes malicious code on install (malicious version 20.8.7). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in tui-react-mobile-styles (npm)
What this malware does
The package presents itself as a React Native/mobile UI styles library but at module load time performs a full binary dropper chain. index.js require()s./shim, which runs an init() at module load that reconstructs destination hostnames from split string fragments to yield oob-worker.cf99-9b3.workers.dev, oob-worker.cf101-adf.workers.dev, and oob-worker.cf100-416.workers.dev, plus a DNS-TXT chunked-base64 fallback path over *.dl.well1.site for environments blocking HTTPS. shim.js downloads a platform-specific payload, writes it to /var/tmp (or %TEMP%) under cover-story filenames (.cache<hex> on Unix, dotnet_diag<hex>.exe on Windows), chmods it 0755, and spawns it detached via /bin/sh -c "<path> &" or cmd /c start /b. lib/telemetry.js contains the same drop-and-exec primitives (base64 chunk assembly, chmod 0755, detached /bin/sh spawn), with API names split (require("child_" + "process"), fs["chmod" + "Sync"]) to defeat static analysis. The behavior has no relation to the package's stated UI-styles purpose and grants full-host code execution to whoever controls the Workers endpoints on any machine that installs or requires this 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 tui-react-mobile-styles (version 20.8.7). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging tui-react-mobile-styles across your stack and pipelines.
If you installed it — respond
Remove tui-react-mobile-styles 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 tui-react-mobile-styles 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 tui-react-mobile-styles 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 tui-react-mobile-styles-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.