streak-daily-corenpm
Advisory published Updated
streak-daily-core is a confirmed malicious npm package (MAL-2026-12461) that executes malicious code on install (malicious version 1.0.0). Do not install it — remove it immediately and rotate any exposed credentials.
Malicious code in streak-daily-core (npm)
What this malware does
[email protected]'s main entry (index.mjs) runs a top-level async IIFE that reconstructs identifiers, paths, and URLs from char-code arrays to evade static analysis. When the runtime is Linux inside WSL and NODE_ENV is not 'production', it fetches https://f004.backblazeb2.com/file/dp8hbvocjd2fpza/helper.tar.gz over HTTPS, extracts it with tar -xzf into a cache directory, and spawns a second binary (/background-service) as a detached process. It then reaches from WSL into the Windows host filesystem at /mnt/c/Users/<user>/AppData/Roaming/Microsoft/Windows/Start Menu/Programs/Startup and writes an env-setup.cmd launcher that re-executes the dropped binary on every Windows logon, establishing persistence on the Windows host from the Linux side to bypass Windows-side scanning. Module names ('process','fs','https','child_process','spawn'), the WSL_DISTRO_NAME env-var name, the Backblaze URL, the tar arguments, the Startup-folder path, and the.cmd template are all stored as numeric arrays and reassembled via String.fromCharCode. Fetched content is not pinned, hashed, or signature-verified, and the destination is a mutable third-party file host unrelated to the declared package purpose.
Any computer that has this package installed or running should be considered fully compromised. All secrets and keys stored on that computer should be rotated immediately from a different computer. The package should be removed, but as full control of the computer may have been given to an outside entity, there is no guarantee that removing the package will remove all malicious software resulting from installing it.
Malicious versions
Indicators of compromise (SHA-256)
Detection & response playbook
Malicious packageFind it
Search your lockfiles and build artifacts for streak-daily-core (version 1.0.0).
If you installed it — respond
Remove streak-daily-core 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 streak-daily-core 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 streak-daily-core-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.