streak-daybucketnpm
streak-daybucket is a confirmed malicious npm package (MAL-2026-12464) 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-daybucket (npm)
What this malware does
[email protected] presents itself as a day-bucket / streak math utility but its index.mjs embeds a hex-encoded Windows PE binary (leading 4D5A90... MZ header) alongside hex-encoded path components that decode to %APPDATA%/Roaming/Microsoft/Windows/Start Menu/Programs/Startup/vite-native-helper.exe. On module load, a try/catch decodes the hex arrays with Buffer.from(hex, 'hex') and writes the executable into the current user's Startup folder via fs.write*. Because the drop runs at top-level module evaluation, any import/require of the package (including transitive consumption) causes the PE to be planted, and Windows will execute it automatically on the next user login, establishing persistent code execution on the installer's host. The path strings, filename vite-native-helper.exe, and payload body are stored as split hex-array literals joined at runtime to evade static string scanning, while the surrounding module ships plain-source math helpers as a cover story.
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-daybucket (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-daybucket across your stack and pipelines.
If you installed it — respond
Remove streak-daybucket 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-daybucket 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-daybucket 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-daybucket-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.