streak-daycountnpm
streak-daycount is a confirmed malicious npm package (MAL-2026-10982) 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-daycount (npm)
What this malware does
[email protected] ships an index.mjs whose top-level async IIFE runs on import. When the host is Linux and NODE_ENV is not 'production', the code enumerates /mnt/c/Users (WSL access to the Windows host filesystem), skips built-in profiles ('Default','Public','All Users'), and identifies real user profiles by the presence of NTUSER.DAT. It then constructs the path AppData/Roaming/Microsoft/Windows/Start Menu/Programs/Startup under that user, downloads a binary from https://f004.backblazeb2.com/file/<bucket>/vite-deps.dat (URL assembled from split fragments p/h/b/f), and writes the bytes as 'vite-native-helper.exe' into the Windows Startup folder — causing the fetched binary to auto-execute on the next Windows logon. The download uses no hash or signature verification, the destination is an anonymous Backblaze B2 bucket unrelated to the package's advertised 'streak day counter' purpose, and the 'vite-native-helper' naming is a decoy referencing an unrelated tool. The bucket identifier is currently a 'YOUR_BUCKET_NAME' placeholder, but the code path is fully wired and activates as soon as it is populated. The Linux+WSL gating specifically targets developer machines that run Node under WSL while backing onto a Windows user profile.
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
Scan your lockfiles (package-lock.json, pnpm-lock.yaml, yarn.lock, requirements.txt, poetry.lock, etc.) and build artifacts for streak-daycount (version 1.0.0). O3 Security's supply-chain scanner checks every dependency against known-malicious package intelligence at install time and in CI, flagging streak-daycount across your stack and pipelines.
If you installed it — respond
Remove streak-daycount 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-daycount 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 streak-daycount 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 streak-daycount-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.