MalwarePublished 5 Aug 2026

mcp-audit-sync-internal (npm) · Malicious Code

Affects mcp-audit-sync-internalSource GCVE Database

Malicious package : remove mcp-audit-sync-internal and rotate any secrets on hosts that installed it.

Data as of 5 Aug 2026, 17:38 UTC

Classification

Malicious package

Published to npm · OSV MAL-2026-12401

What to do

Remove mcp-audit-sync-internal 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
npmmcp-audit-sync-internal	Affected =99.9.9	Fixed in–

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Description

The npm package mcp-audit-sync-internal version 99.9.9 contains malicious code that executes automatically during installation on Windows systems. It runs a hidden PowerShell process that downloads and executes an unverified executable from an anonymous file host. This behavior enables arbitrary code execution on the host machine without user awareness. The package metadata attempts to disguise this activity with misleading descriptions and filenames.

Impact

This malicious package enables arbitrary code execution on Windows hosts during npm install, potentially allowing attackers to run any code with the privileges of the installing user. The unverified and anonymous nature of the downloaded payload increases the risk of executing unknown and potentially harmful software. This compromises system integrity and security without user consent or awareness.

Defensive guidance

Users should avoid installing mcp-audit-sync-internal version 99.9.9. It is recommended to verify package authenticity before installation, avoid packages from untrusted sources, and monitor for suspicious preinstall scripts. Since this is a malicious package, removal and replacement with trusted alternatives is advised.

Summary

The mcp-audit-sync-internal npm package at version 99.9.9 declares a preinstall script that runs 'node index.js'. On Windows, this script spawns a hidden PowerShell process which downloads a ZIP archive from an unrelated anonymous file hosting service (https://files.catbox.moe/5khq55.zip). The ZIP is extracted into the temporary directory, and an executable named Verification_Tool.exe inside it is launched. The remote artifact is neither pinned nor verified by hash or signature, and the entire fetch-and-execute process is hidden from the user via PowerShell's -WindowStyle Hidden option. This results in automatic arbitrary code execution on any Windows system that installs this package. The package's metadata and executable filename are deceptive, serving as cover stories inconsistent with the actual malicious behavior.

References

npmjs.com/package/mcp-audit-sync-internal/v/99.9.9 (opens in a new tab)

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What to do

Affected software

Description

AI analysisMachine-generated, updated 5 Aug 2026, 17:38 UTC

Technical details

References

Community reviews