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bumper-guard@0.2.5: Malicious npm security report (Block) | LPM Firewall

registry / bumper-guard / 0.2.5

bumper-guard@0.2.5

A plain-language safety net for vibe coders. Pauses risky things your AI assistant (Claude Code, Cursor, Codex CLI, Copilot CLI) is about to do, explains them in plain English, and lets you decide.

AI Security Review

scanned 3h ago · by lpm-firewall-ai

Installing the package automatically modifies detected AI-agent control files, starts a background daemon, and creates login persistence. These actions occur without an explicit setup command.

Static reason

One or more suspicious static signals were detected.; source matched previously finalized malicious package; routed for review; source fingerprint signature matched known malicious package; routed for review

Trigger

npm postinstall during package installation

Impact

The package gains a persistent interception point for agent tool requests and changes several unrelated user-level agent configurations.

Mechanism

automatic AI-agent hook injection and daemon persistence

Attack narrative

On installation, the postinstall hook detects user-level Claude Code, Cursor, Copilot, and Codex directories and writes global integrations into them. It then launches the package daemon detached and enables operating-system login persistence. The hooks receive agent tool inputs, giving the persisted package a control point over later agent actions. This is unconsented lifecycle mutation of broad, foreign AI-agent control surfaces.

Rationale

The automatic postinstall chain injects hooks into multiple detected AI-agent configurations and establishes background persistence. This meets the install-hook abuse blocking policy even though the inspected hook transport is local and no self-dependency was found.

Evidence

package.jsonsrc/installers/postinstall.jssrc/installers/autostart.jssrc/installers/claude-code.jssrc/hook-scripts/claude-code.js~/.claude/settings.json~/.cursor/hooks.json

Source & flagged code

9 flagged · loading source

package.jsonView file

•scripts.postinstall = node src/installers/postinstall.js || true

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node src/installers/postinstall.js || true

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg

src/installers/autostart.jsView file

3Trigger-reachable persistence chain: scripts.postinstall -> src/installers/postinstall.js -> src/installers/autostart.js L3: const path = require("path"); L4: const { execFileSync } = require("child_process"); L5: ... L10: L11: const BIN_PATH = path.join(__dirname, "..", "..", "bin", "bumper.js"); L12: const LAUNCH_AGENT_LABEL = "com.bumper.autostart"; ... L26: const WIN_STARTUP_DIR = () => L27: path.join(process.env.APPDATA || path.join(os.homedir(), "AppData", "Roaming"), "Microsoft", "Windows", "Start Menu", "Programs", "Startup"); L28: const WIN_LAUNCHER_PATH = () => path.join(WIN_STARTUP_DIR(), "BumperAutostart.vbs"); ... L79: fs.writeFileSync(LAUNCH_AGENT_PATH, plistContents()); L80: run("launchctl", ["load", "-w", LAUNCH_AGENT_PATH]); L81: return { platform: "darwin", mechanism: "

High

Trigger Reachable Persistence

A manifest entrypoint or package-local install chain reaches persistence behavior.

src/installers/autostart.jsView on unpkg · L3

•matchType = normalized_sha256 matchedPackage = bumper-guard@0.2.4 matchedPath = src/installers/autostart.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 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.

src/installers/autostart.jsView on unpkg

•matchType = malicious_source_fingerprint_signature signature = 73280a514388764a signatureType = suspicious_hashes sourceLabel = final_verdict:malicious matchedPackage = bumper-guard@0.2.4 matchedPath = src/installers/autostart.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 similarity = 1.000 shingleOverlap = 19 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.

src/installers/autostart.jsView on unpkg

3const path = require("path"); L4: const { execFileSync } = require("child_process"); L5: ... L10: L11: const BIN_PATH = path.join(__dirname, "..", "..", "bin", "bumper.js"); L12: const LAUNCH_AGENT_LABEL = "com.bumper.autostart"; ... L26: const WIN_STARTUP_DIR = () => L27: path.join(process.env.APPDATA || path.join(os.homedir(), "AppData", "Roaming"), "Microsoft", "Windows", "Start Menu", "Programs", "Startup"); L28: const WIN_LAUNCHER_PATH = () => path.join(WIN_STARTUP_DIR(), "BumperAutostart.vbs"); ... L79: fs.writeFileSync(LAUNCH_AGENT_PATH, plistContents()); L80: run("launchctl", ["load", "-w", LAUNCH_AGENT_PATH]); L81: return { platform: "darwin", mechanism: "launchd LaunchAgent", ref: LAUNCH_AGENT_PATH };

Medium

Install Persistence

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

src/installers/autostart.jsView on unpkg · L3

src/daemon.jsView file

•matchType = normalized_sha256 matchedPackage = bumper-guard@0.2.4 matchedPath = src/daemon.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 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.

src/daemon.jsView on unpkg

src/account.jsView file

•matchType = normalized_sha256 matchedPackage = bumper-guard@0.2.4 matchedPath = src/account.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 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.

src/account.jsView on unpkg

src/policy.jsView file

•matchType = normalized_sha256 matchedPackage = bumper-guard@0.2.4 matchedPath = src/policy.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 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.

src/policy.jsView on unpkg

Source & flagged code

9 flagged

package.jsonView file

Lines 1-35json

1{

2 "name": "bumper-guard",

3 "version": "0.2.5",

4 "description": "A plain-language safety net for vibe coders. Pauses risky things your AI assistant (Claude Code, Cursor, Codex CLI, Copilot CLI) is about to do, explains them in plain English, and lets you decide.",

5 "bin": {

6 "bumper": "bin/bumper.js"

7 },

8 "main": "src/daemon.js",

9 "type": "commonjs",

10 "files": [

11 "bin",

12 "src",

13 "web",

14 "bumper.policy.example.yaml",

15 "README.md",

16 "LICENSE"

17 ],

18 "scripts": {

19 "start": "node bin/bumper.js start",

20 "postinstall": "node src/installers/postinstall.js || true"

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L20

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg · L20

21 },

22 "dependencies": {

23 "@modelcontextprotocol/sdk": "^1.12.0",

24 "commander": "^12.1.0",

25 "express": "^4.21.2",

26 "js-yaml": "^4.1.0",

27 "zod": "^3.23.8"

28 },

29 "engines": {

30 "node": ">=18"

31 },

32 "license": "SEE LICENSE IN LICENSE",

33 "homepage": "https://bumper-guard.pages.dev"

34}

35

src/installers/autostart.jsView file

Lines 1-23javascript

1const fs = require("fs");

2const os = require("os");

3const path = require

src/daemon.jsView file

•matchType = normalized_sha256 matchedPackage = bumper-guard@0.2.4 matchedPath = src/daemon.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 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.

src/daemon.jsView on unpkg

src/account.jsView file

•matchType = normalized_sha256 matchedPackage = bumper-guard@0.2.4 matchedPath = src/account.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 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.

src/account.jsView on unpkg

src/policy.jsView file

•matchType = normalized_sha256 matchedPackage = bumper-guard@0.2.4 matchedPath = src/policy.js matchedIdentity = npm:YnVtcGVyLWd1YXJk:0.2.4 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.

src/policy.jsView on unpkg