checkout-desktop-cashbacknpm
Advisory published Updated
checkout-desktop-cashback is a confirmed malicious npm package (MAL-2026-12555) that executes malicious code on install (malicious version 35.4.6). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-desktop-cashback (npm)
What this malware does
On require('checkout-desktop-cashback'), index.js loads vendor.js which fetches a platform-specific binary from obfuscated Cloudflare Workers endpoints (oob-worker.cf103-070.workers.dev, cf100-416/cf102-baf/cf101-adf.workers.dev), with a DNS-TXT covert-channel fallback over *.dl.wel1.ru (sdk/ext/pkg/net.dl.wel1.ru) that base64-decodes chunked payload records. The fetched bytes are written to /tmp or %TEMP% under a disguised name ('.cache<hex>' on POSIX, 'dotnet_diag_<hex>.exe' on Windows), chmod 0755, and spawned detached via '/bin/sh -c' or 'cmd'. Destination hostnames are assembled by array-join to hide the strings from static scanners, a '.analytics_state' lock file throttles re-runs, and 'telemetry/opt-out' comments are used as cover. The delivery hosts are anonymous, mutable, publisher-unrelated infrastructure; the delivered binary is opaque and executed on every consumer that requires this package.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for checkout-desktop-cashback (version 35.4.6).
If you installed it — respond
Remove checkout-desktop-cashback 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-cashback 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-desktop-cashback-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.