MalwarePublished 5 Aug 2026Updated 25 Aug 2026

streak-daykit (npm) · Malicious Code

Affects streak-daykitSource GCVE Database

Malicious package : remove streak-daykit and rotate any secrets on hosts that installed it.

Data as of 26 Oct 2026, 16:15 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-12466

What to do

Remove streak-daykit 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-daykit	Affected =1.0.0	Fixed in–

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Description

The streak-daykit npm package version 1.0.0 contains malicious code that, when imported, executes a Linux-gated routine to detect a Windows Subsystem for Linux (WSL) environment. It then retrieves an executable from a hex-obfuscated URL hosted on a typosquatted domain and writes this payload as an autostart executable in the Windows user's startup folder, establishing persistence. The payload is attacker-controlled and executed upon the next Windows sign-in. There is no integrity verification or publisher validation for the fetched binary.

Impact

This malicious package enables an attacker to establish persistent, user-level code execution on Windows hosts running WSL by dropping and executing an attacker-controlled executable at startup. This can lead to unauthorized code execution, potential data compromise, and further system compromise. The lack of integrity checks or publisher validation increases the risk of undetected compromise.

Defensive guidance

Users should immediately remove streak-daykit version 1.0.0 from their environments and avoid installing or importing this package. Conduct a thorough investigation for the presence of the dropped executable (vite-native-helper.exe) in the Windows startup folder and remove it if found. Monitor for suspicious activity related to this threat.

Summary

The streak-daykit package version 1.0.0 includes a top-level immediately-invoked function expression (IIFE) in its main entry point (index.mjs) that detects if it is running in a WSL environment by probing the /mnt/c directory. Upon detection, it locates the active Windows user profile by accessing the NTUSER.DAT file, then downloads a binary executable from a hex-obfuscated URL pointing to backlazeb2.com, a typosquat of Backblaze B2's domain. This executable is saved as vite-native-helper.exe in the user's Windows startup folder to achieve user-level persistence. The code uses obfuscation techniques such as splitting hex arrays and decoding them at runtime. No version pinning, hash checks, or publisher verification are present, allowing execution of opaque attacker-controlled code on the victim's Windows system at next login.

References

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What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Aug 2026, 17:47 UTC

Technical details

References

Community reviews