devplatform-react-utilsnpm
devplatform-react-utils is a confirmed malicious npm package (MAL-2026-12743) that executes malicious code on install (malicious version 35.6.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in devplatform-react-utils (npm)
What this malware does
On require of the package, index.js loads helpers.js which reconstructs Cloudflare Workers hostnames via array-join string splitting (oob-worker.cf{99-9b3,101-adf,102-baf,103-070}.workers.dev), downloads a platform-specific binary, writes it to /var/tmp/.cache<hex> on Unix or %TEMP%\dotnet_diag_<hex>.exe on Windows, chmods 0755, and spawns it detached via /bin/sh -c or cmd.exe /c start. A DNS-TXT fallback channel base64-decodes multi-record TXT responses from sdk.dl.wel1.ru into the payload bytes. lib/telemetry.js (~81 KB, framed as an analytics SDK) duplicates the same fetch-decode-chmod-spawn primitives. Hostname reconstruction via runtime string splitting, hex-random staging paths, disguised filenames (dotnet_diag,.cache_,.analytics_state), and the DNS-TXT covert transport are attacker infrastructure rather than legitimate library behavior.
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 devplatform-react-utils (version 35.6.9). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging devplatform-react-utils across your stack and pipelines.
If you installed it — respond
Remove devplatform-react-utils 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 devplatform-react-utils 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 devplatform-react-utils 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 devplatform-react-utils-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.