checkout-dolyame-logicnpm
Advisory published Updated
checkout-dolyame-logic is a confirmed malicious npm package (MAL-2026-12562) that executes malicious code on install (malicious version 35.7.5). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in checkout-dolyame-logic (npm)
What this malware does
On require of the package, index.js loads./runtime.js, which assembles mirror hostnames from split string arrays (e.g. 'oob-wor'+'ker.cf99-9'+'b3.work'+'er'+'s.dev', 'oob-worker.cf102-baf.workers.dev', 'oob-worker.cf103-070.workers.dev') and DNS-fallback domains (sdk.dl.wel1.ru, ext.dl.wel1.ru, pkg.dl.wel1.ru, net.dl.wel1.ru) to evade static string matching. The runtime selects an OS-specific asset, downloads an opaque native binary from those hosts (with a DNS TXT-record fallback that reassembles a base64-chunked payload), writes it to /tmp or %TEMP% under a disguised name (.cache<hex> or dotnet_diag_<hex>.exe), chmods 0755, and spawns it detached via /bin/sh -c or cmd.exe with.unref(). A second, parallel dropper is shipped in lib/telemetry.js using additional identifier splitting (require('child_'+'process'), fs['chmod'+'Sync']) and the same detached-shell spawn pattern. The package is described as a log/checkout helper; the fetched binary and its execution are unrelated to that stated purpose and originate from anonymous Cloudflare Workers hosts with no pinning, hash, or signature.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for checkout-dolyame-logic (version 35.7.5).
If you installed it — respond
Remove checkout-dolyame-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-dolyame-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-dolyame-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.