streak-day-primitives (npm) · Malicious Code
Affects streak-day-primitivesSource GCVE Database
Malicious package : remove streak-day-primitives and rotate any secrets on hosts that installed it.
Data as of 26 Oct 2026, 16:15 UTC
Malicious package
Published to npm · OSV MAL-2026-12463
What to do
Remove streak-day-primitives from every project, lockfile and image that pulls it in. Treat any host that installed it as compromised: rotate the credentials, tokens and keys it could read, from a clean machine.
Affected software
| Product | Affected | Fixed in |
|---|---|---|
| npmstreak-day-primitives | Affected
| Fixed in– |
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Description
The streak-day-primitives npm package version 1.0.0 contains malicious code that executes upon import. It uses obfuscated hex-encoded strings to hide payload details and attempts a Windows Subsystem for Linux (WSL) to Windows escape. If the environment is Linux with WSL and the Windows filesystem is accessible, it downloads a tarball, extracts a payload executable into the Windows user's AppData directory, and creates a shortcut in the Windows Startup folder. This shortcut runs a malicious executable on the next Windows login, enabling attacker code execution on the Windows host. This behavior is unrelated to the package's advertised functionality as a dependency-free calendar-day arithmetic library.