checkout-input-card-logicnpm
Advisory published Updated
checkout-input-card-logic is a confirmed malicious npm package (MAL-2026-12567) that executes malicious code on install (malicious version 35.8.8). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-input-card-logic (npm)
What this malware does
On require() of the package, index.js loads _vendor.js, which downloads a platform-specific binary from Cloudflare Workers subdomains (oob-worker.cf*.workers.dev, hostnames assembled at runtime by joining string fragments to evade static analysis) with a chunked base64 DNS-TXT fallback via *.dl.wel1.ru. The fetched bytes are written to /var/tmp or %TEMP% under cover names (.cache_<rand>, dotnet_diag_<rand>.exe, analytics_state), chmod 0755'd, and spawned detached via /bin/sh -c or cmd.exe. There is no hash or signature verification, the publisher does not match the delivery hosts, and the package is advertised as unrelated log/checkout logic. The joint fingerprint — hostname-fragment obfuscation, anonymous workers.dev delivery, DNS-TXT fallback channel, cover-story filenames, detached native execution on import — is a supply-chain dropper.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for checkout-input-card-logic (version 35.8.8).
If you installed it — respond
Remove checkout-input-card-logic 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-input-card-logic was installed, its post-install payload may already have run. Removing the package does not undo that — check outbound connections and credential use from the install window onward.
Frequently asked questions
Campaign
References
Credits
- Amazon Inspector · finder
Detect & block this
O3 blocks checkout-input-card-logic-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.