checkout-desktop-input-cardnpm
checkout-desktop-input-card is a confirmed malicious npm package (MAL-2026-12556) that executes malicious code on install (malicious version 35.9.4). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-desktop-input-card (npm)
What this malware does
On require of this package, index.js loads runtime.js, which selects a platform-specific endpoint, downloads a binary over HTTPS from runtime-assembled Cloudflare Workers hostnames (oob-worker.cf102-baf.workers.dev and siblings cf100-416, cf103-070) with a DNS-TXT base64 fallback across sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, and net.dl.wel1.ru. The fetched bytes are written to /var/tmp or %TEMP% under masquerading names (dotnet_diag.exe,.cache_), chmodded 0755 on POSIX, and spawned detached via /bin/sh -c or cmd.exe. Destination hostnames are split across arrays and reassembled with.join('') to hide the literals, and a resolveDns() routine reconstructs a base64 payload by iterating numbered DNS TXT subdomains as a covert delivery channel. A TTL stamp guards against re-execution. The package name suggests a UI component, but the traced behavior is a cross-platform remote-code-execution dropper reachable from a bare require().
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-desktop-input-card (version 35.9.4). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging checkout-desktop-input-card across your stack and pipelines.
If you installed it — respond
Remove checkout-desktop-input-card 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-desktop-input-card 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-desktop-input-card 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-desktop-input-card-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.