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local-mcp@3.0.357: AI-agent control-surface risk | LPM Firewall

registry / local-mcp / 3.0.357

local-mcp@3.0.357

Let ChatGPT, Claude, Cursor & any MCP client actually use your Mac — read & reply to email, manage your calendar, text over iMessage, find files, work with Teams, Slack & Office. On your Mac, no API keys, free.

AI Security Review

scanned 16d ago · by lpm-firewall-ai

LPM flags this version as an AI-agent control-surface risk. A global npm install silently configures multiple foreign AI clients to launch local-mcp, downloads remote executables, and establishes a persistent tray LaunchAgent. The downloaded binary is executed by the setup health check.

Static reason

High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review; source fingerprint signature matched known malicious package; routed for review; previous stored version diff introduced dangerous source

Trigger

npm global install on macOS

Impact

Foreign MCP clients are modified to execute package-controlled code; remote payloads run with the installing user's privileges.

Mechanism

postinstall AI-client config hijack, remote binary execution, and LaunchAgent persistence

Policy narrative

On global macOS installation, postinstall invokes setup without user interaction. Setup discovers several third-party AI clients, rewrites their MCP configuration to launch local-mcp, removes office-mcp, downloads unverified server/proxy/tray archives, and executes the server health check. It also installs a KeepAlive LaunchAgent for the downloaded tray application.

Rationale

This is an unconsented install-time mutation of broad foreign AI-agent control surfaces, coupled with remote payload download and execution. The restrictive guards do not provide user consent or remove the concrete chain.

Evidence

package.jsonpostinstall.jssetup.jsdownload.jsindex.js~/Library/Application Support/Claude/claude_desktop_config.json~/.cursor/mcp.json

Source & flagged code

13 flagged · loading source

package.jsonView file

•scripts.postinstall = node postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node postinstall.js

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg

download.jsView file

7L8: const https = require('https') L9: const http = require('http') ... L12: const os = require('os') L13: const { execFileSync, execSync } = require('child_process') L14: ... L18: const tarBin = process.platform === 'win32' L19: ? path.join(process.env.SystemRoot || 'C:\\Windows', 'System32', 'tar.exe') L20: : 'tar'

Critical

Same File Env Network Execution

A single source file combines environment access, network access, and code or shell execution with blocking evidence.

download.jsView on unpkg · L7

351Trigger-reachable chain: manifest.main -> index.js -> download.js L351: if (fs.existsSync(systemTrayApp) && trayApp !== systemTrayApp) { L352: try { execFileSync('rm', ['-rf', systemTrayApp], { stdio: 'pipe' }) } catch { /* ignorar */ } L353: } ... L364: L365: const url = `https://download.local-mcp.com/local-mcp-tray-${version}-darwin-universal.tar.gz` L366: process.stderr.write(`\nDescargando tray v${version}...\n`) L367:

Critical

Trigger Reachable Dangerous Capability

A package entrypoint or install-time lifecycle script reaches a source file with blocking dangerous behavior.

download.jsView on unpkg · L351

•matchType = previous_version_dangerous_delta matchedPackage = local-mcp@3.0.331 matchedIdentity = npm:bG9jYWwtbWNw:3.0.331 similarity = 0.500 summary = stored previous version shares package body but lacks this dangerous source file

Critical

Previous Version Dangerous Delta

This package version adds a dangerous source file absent from the previous stored version; route for source-aware review.

download.jsView on unpkg

12const os = require('os') L13: const { execFileSync, execSync } = require('child_process') L14:

High

Child Process

Package source references child process execution.

download.jsView on unpkg · L12

351if (fs.existsSync(systemTrayApp) && trayApp !== systemTrayApp) { L352: try { execFileSync('rm', ['-rf', systemTrayApp], { stdio: 'pipe' }) } catch { /* ignorar */ } L353: } ... L364: L365: const url = `https://download.local-mcp.com/local-mcp-tray-${version}-darwin-universal.tar.gz` L366: process.stderr.write(`\nDescargando tray v${version}...\n`) L367:

High

Command Output Exfiltration

Source combines command execution, command-output handling, and outbound requests; review data flow before blocking.

download.jsView on unpkg · L351

7L8: const https = require('https') L9: const http = require('http') ... L12: const os = require('os') L13: const { execFileSync, execSync } = require('child_process') L14: ... L17: function extractTar(tarPath, destDir) { L18: const tarBin = process.platform === 'win32' L19: ? path.join(process.env.SystemRoot || 'C:\\Windows', 'System32', 'tar.exe') L20: : 'tar' ... L30: const CACHE_DIR = process.platform === 'win32' L31: ? path.join(process.env.LOCALAPPDATA || path.join(os.homedir(), 'AppData', 'Local'), 'local-mcp', 'bin')

High

Sandbox Evasion Gated Capability

Source gates dangerous network, credential, or execution behavior behind CI, host, platform, time, or geo fingerprint checks.

download.jsView on unpkg · L7

•matchType = normalized_sha256 matchedPackage = local-mcp@3.0.348 matchedPath = download.js matchedIdentity = npm:bG9jYWwtbWNw:3.0.348 similarity = 1.000 summary = normalized source hash matched finalized malicious source

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

download.jsView on unpkg

•matchType = malicious_source_fingerprint_signature signature = 5fd9d9a49e3df6eb signatureType = suspicious_hashes sourceLabel = final_verdict:malicious matchedPackage = local-mcp@3.0.348 matchedPath = download.js matchedIdentity = npm:bG9jYWwtbWNw:3.0.348 similarity = 1.000 shingleOverlap = 4 summary = package final verdict is malicious

High

Known Malware Source Fingerprint Signature

Source fingerprint signature matches a known malicious package signature; route for source-aware review.

download.jsView on unpkg

7L8: const https = require('https') L9: const http = require('http') ... L12: const os = require('os') L13: const { execFileSync, execSync } = require('child_process') L14: ... L17: function extractTar(tarPath, destDir) { L18: const tarBin = process.platform === 'win32' L19: ? path.join(process.env.SystemRoot || 'C:\\Windows', 'System32', 'tar.exe') L20: : 'tar' ... L30: const CACHE_DIR = process.platform === 'win32' L31: ? path.join(process.env.LOCALAPPDATA || path.join(os.homedir(), 'AppData', 'Local'), 'local-mcp', 'bin')

Medium

Install Persistence

Source writes installer persistence such as shell profile or service configuration.

download.jsView on unpkg · L7

index.jsView file

•matchType = normalized_sha256 matchedPackage = local-mcp@3.0.348 matchedPath = index.js matchedIdentity = npm:bG9jYWwtbWNw:3.0.348 similarity = 1.000 summary = normalized source hash matched finalized malicious source

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

index.jsView on unpkg

setup.jsView file

•matchType = normalized_sha256 matchedPackage = local-mcp@3.0.348 matchedPath = setup.js matchedIdentity = npm:bG9jYWwtbWNw:3.0.348 similarity = 1.000 summary = normalized source hash matched finalized malicious source

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

setup.jsView on unpkg

Source & flagged code

13 flagged

package.jsonView file

Lines 1-30json

1{

2 "name": "local-mcp",

3 "version": "3.0.357",

4 "description": "Let ChatGPT, Claude, Cursor & any MCP client actually use your Mac — read & reply to email, manage your calendar, text over iMessage, find files, work with Teams, Slack & Office. On your Mac, no API keys, free.",

5 "main": "index.js",

6 "bin": {

7 "local-mcp": "index.js"

8 },

9 "scripts": {

10 "postinstall": "node postinstall.js"

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L10

Medium

Ambiguous Install Lifecycle Script

Install-time lifecycle script is not statically allowlisted and needs review.

package.jsonView on unpkg · L10

11 },

12 "files": [

13 "index.js",

14 "download.js",

15 "setup.js",

16 "postinstall.js",

17 "README.md"

18 ],

19 "engines": {

20 "node": ">=18"

21 },

22 "os": [

23 "darwin"

24 ],

25 "keywords": [

26 "mcp",

27 "model-context-protocol",

28 "mcp-server",

29 "claude",

30 "claude-desktop",

download.jsView file

Lines 1-32javascript

1'use strict'

2/**

3 * download.js — descarga y cachea el binario standalone de LMCP desde R2.

4 * El binario fue compilado con PyInstaller — no requiere Python instalado.

5 * Cache: ~/.local/share/local-mcp/bin/{version}/

6 */

7

8const https = require('https')

index.jsView file

•matchType = normalized_sha256 matchedPackage = local-mcp@3.0.348 matchedPath = index.js matchedIdentity = npm:bG9jYWwtbWNw:3.0.348 similarity = 1.000 summary = normalized source hash matched finalized malicious source

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

index.jsView on unpkg

setup.jsView file

•matchType = normalized_sha256 matchedPackage = local-mcp@3.0.348 matchedPath = setup.js matchedIdentity = npm:bG9jYWwtbWNw:3.0.348 similarity = 1.000 summary = normalized source hash matched finalized malicious source

High

Known Malware Source Similarity

Source file is highly similar to a previously finalized malicious package; route for source-aware review.

setup.jsView on unpkg