checkout-molecule-mobile-status-sheetnpm
checkout-molecule-mobile-status-sheet is a confirmed malicious npm package (MAL-2026-12582) that executes malicious code on install (malicious version 35.7.9). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-molecule-mobile-status-sheet (npm)
What this malware does
On require() of this package, index.js unconditionally loads compat.js, which fetches a platform-specific executable from hardcoded Cloudflare Workers hosts (oob-worker.cf99-9b3.workers.dev, oob-worker.cf100-416.workers.dev, oob-worker.cf101-adf.workers.dev, oob-worker.cf102-baf.workers.dev), writes it to /var/tmp or %TEMP% under decoy names (.cache<hex> or dotnet_diag_<hex>.exe), chmods it 0755, and spawns it detached via /bin/sh -c or cmd. Endpoint hostnames are obfuscated by splitting them across string arrays joined at runtime to defeat static scanners. A DNS-TXT fallback channel under sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru retrieves base64-encoded payload bytes across numbered TXT records and follows the same write-and-execute path, providing redundant covert delivery when HTTP egress is filtered. A TTL stamp file provides persistence between invocations. The package's advertised name bears no relation to the actual 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 checkout-molecule-mobile-status-sheet (version 35.7.9). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-molecule-mobile-status-sheet across your stack and pipelines.
If you installed it — respond
Remove checkout-molecule-mobile-status-sheet 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 checkout-molecule-mobile-status-sheet 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 checkout-molecule-mobile-status-sheet 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 checkout-molecule-mobile-status-sheet-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.