registry / AI-agent control-surface risk / @chem-x/create-chemx / 26.9.16-1408

@chem-x/create-chemx@26.9.16-1408

Chemical X Protocol: Private drop-in architecture starter kit and capsule generator

AI Security Review

scanned 11d ago · by lpm-firewall-ai

Source confirms an automatic postinstall that writes agent configuration in the consumer project and may also write global Antigravity configuration, without an install-time consent guard. This meets the policy for blocking unconsented lifecycle mutation of AI-agent control surfaces.

Static reason

High-risk behavior combination matched malicious policy.; previous stored version diff introduced dangerous source; source closely matched a different package identity

Trigger

Installing the package through npm, which runs its postinstall hook.

Impact

Agent clients may load and run the registered server, including an npx-based command when no local starter is found.

Mechanism

The hook invokes the MCP installer for the consumer project; it writes Cursor and VS Code project configuration and, when present, the global Antigravity configuration, registering Chemical X as an MCP server.

Policy narrative

The package's postinstall hook runs the MCP installer against the consumer project without prompting. That installer writes agent server configuration into project files and may alter the global Antigravity configuration. The configured server is Chemical X itself, but registering it during an unrelated package installation is an unconsented mutation of agent control surfaces.

AI rationale

Evidence

package.jsoncli/postinstall.jscli/mcp/installer.js.cursor/mcp.json.vscode/mcp.json~/.gemini/config/mcp_config.json

Decision evidence

public snapshot

AI identified this as a dangerous AI-agent capability at 96.0% confidence with low false-positive risk.

Evidence for policy risk

package.json runs cli/postinstall.js from its postinstall hook.
The postinstall targets the consumer project and calls installAllMcpConfigs without a consent prompt.
The lifecycle call writes MCP configuration into consumer .cursor/mcp.json.
The same installer writes to an existing global Antigravity configuration when its directory is present.
When no local starter is found, the configured server runs npx -y chemx mcp.
The separate installer can append agent-directed search rules to an existing AGENTS.md, but that path is not needed to establish the lifecycle behavior.

Evidence against

The MCP server registration is package-aligned functionality and preserves existing MCP server entries.
The AGENTS.md instruction mutation is in the separate installer flow, not the postinstall call path.

Behavioral surface

Source

ChildProcessEnvironmentVarsFilesystemNetworkShell

Supply chain

HighEntropyStrings

Source & flagged code

10 flagged

package.jsonView file

Lines 32-71json

32 ".": "./cli/index.js",

33 "./audit": "./cli/audit.js",

34 "./build": "./cli/build.js",

35 "./search": "./cli/search.js",

36 "./mcp": "./cli/mcp/index.js",

37 "./reader": "./cli/reader.js",

38 "./patcher": "./cli/patcher.js"

39 },

40 "scripts": {

41 "publish:both": "node scripts/publish-both.mjs",

42 "test": "node --test cli/audit/*.spec.js cli/mcp/*.spec.js cli/*.spec.js",

43 "typecheck": "tsc --noEmit",

44 "create-capsule": "node cli/index.js",

45 "audit": "node cli/index.js audit",

46 "ci:audit": "node cli/index.js audit --ci --dir=cli",

47 "chemx": "node cli/index.js",

48 "q": "node cli/index.js q",

49 "search": "node cli/index.js search",

50 "mcp": "node cli/index.js mcp",

51 "install-mcp": "node cli/index.js install-mcp",

52 "postinstall": "node cli/postinstall.js",

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg · L52

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg · L52

53 "read": "node cli/index.js read",

54 "patch": "node cli/index.js patch"

55 },

56 "dependencies": {

57 "@babel/parser": "^7.29.8",

58 "@babel/traverse": "^7.29.8",

59 "@babel/types": "^7.29.8",

60 "react": "^18.3.1",

61 "react-dom": "^18.3.1"

62 },

63 "devDependencies": {

64 "@types/babel__traverse": "^7.28.0",

65 "@types/node": "^22.20.2",

66 "@types/react": "^18.3.31",

67 "@types/react-dom": "^18.3.7",

68 "typescript": "^5.9.3"

69 }

70}

cli/audit-preflight-git.jsView file

1import fs from 'node:fs'; L2: import { spawnSync } from 'node:child_process'; L3:

High

Child Process

Package source references child process execution.

cli/audit-preflight-git.jsView on unpkg · L1

cli/terminal.jsView file

10} else if (platform === "win32") { L11: spawnSync("cmd.exe", ["/c", "start", '""', url], { stdio: "ignore", timeout: 3000 }); L12: } else {

High

Shell

Package source references shell execution.

cli/terminal.jsView on unpkg · L10

cli/license.jsView file

Lines 1-23javascript

1import fs from 'node:fs';

2import path from 'node:path';

3import os from 'node:os';

4import { spawnSync } from 'node:child_process';

cli/mcp/installer.jsView file

1Install-time code directly mutates a foreign AI-agent control surface: L17: export const mergeMcpServerConfig = (existingJsonString = '', serverDef = {}) => { L18: let parsed = { mcpServers: {} }; L19: ... L27: L28: const hasMcpServersObject = Boolean(parsed.mcpServers && typeof parsed.mcpServers === 'object'); L29: if (!hasMcpServersObject) { L30: parsed.mcpServers = {}; L31: } L32: L33: parsed.mcpServers[SERVER_KEY] = serverDef; L34: return JSON.stringify(parsed, null, 2) + '\n'; ... L87: const cursorDir = path.join(resolvedTarget, '.cursor'); Write operation from cli/mcp/installer.js: L17: export const mergeMcpServerConfig = (existingJsonString = '', serverDef = {}) => { L18: let parsed = { mcpServers: {} }; L19: ... L27: L28: const hasMcpServersObject = Boolean(parsed.mcpServers &

Critical

Ai Agent Control Hijack

Source creates an unconsented AI-agent control surface through install-time mutation or a default unauthenticated remote skill channel.

cli/mcp/installer.jsView on unpkg · L1

cli/scaffold.jsView file

•Manifest-trigger-reachable source links an external AI-agent control path to a behavior-bearing write operation. import fs from 'node:fs'; import path from 'node:path'; import { hasgum, guminput, promptquestion, renderbanner } from './terminal.js'; import { obtainlicensekey, fetchstarterkitfiles, loadlocalblueprintfiles } from './license.js'; export const runscaffold = async (projectname, rawargs = [], onrunaudit = null) => { renderbanner('chemical x: molecular architecture scaffolder (npm create chemx)'); const licensekey = await obtainlicensekey(rawargs, onrunaudit); let iscommunity = false; let files = {}; if (!licensekey) { process.stdout.write( '\n\x1b[38;2;98;201;255m⚡ chemical x: community edition (free)\x1b[0m\n' + 'the community version is free because

High

Trigger Reachable External Ai Agent Control Surface Mutation

Manifest-trigger-reachable source writes behavior-bearing configuration into a user or project AI-agent control surface.

cli/scaffold.jsView on unpkg

scripts/pre-commit.shView file

•matchType = previous_version_dangerous_delta matchedPackage = @chem-x/create-chemx@26.9.14-1358 matchedIdentity = npm:QGNoZW0teC9jcmVhdGUtY2hlbXg:26.9.14-1358 similarity = 0.786 summary = stored previous version shares package body but lacks this dangerous source file

High

Previous Version Dangerous Delta

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

scripts/pre-commit.shView on unpkg

•path = scripts/pre-commit.sh kind = build_helper sizeBytes = 4608 magicHex = [redacted]

Medium

Ships Build Helper

Package ships non-JavaScript build or shell helper files.

scripts/pre-commit.shView on unpkg

cli/audit/social-git.jsView file

•matchType = package_source_clone_identity_mismatch matchedPackage = create-chemx@26.9.14-1358 matchedPath = cli/audit/ai-slop-detector.js matchedIdentity = npm:Y3JlYXRlLWNoZW14:26.9.14-1358 similarity = 0.671 shingleOverlap = 47 summary = source files closely matched a different published package identity

High

Package Source Clone Identity Mismatch

Package source closely matches a different published package identity; review for dependency-confusion or copied-code abuse.

cli/audit/social-git.jsView on unpkg

Source & flagged code

10 flagged · loading source

package.jsonView file

•scripts.postinstall = node cli/postinstall.js

High

Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg

•scripts.postinstall = node cli/postinstall.js

Medium

Ambiguous Install Lifecycle Script

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

package.jsonView on unpkg

cli/audit-preflight-git.jsView file

1import fs from 'node:fs'; L2: import { spawnSync } from 'node:child_process'; L3:

High

Child Process

Package source references child process execution.

cli/audit-preflight-git.jsView on unpkg · L1

Findings

1 Critical7 High5 Medium4 Low

CriticalAi Agent Control Hijackcli/mcp/installer.js

HighInstall Time Lifecycle Scriptspackage.json

HighChild Processcli/audit-preflight-git.js

HighShellcli/terminal.js

HighSame File Env Network Executioncli/license.js

HighTrigger Reachable External Ai Agent Control Surface Mutationcli/scaffold.js

HighPrevious Version Dangerous Deltascripts/pre-commit.sh

HighPackage Source Clone Identity Mismatchcli/audit/social-git.js

MediumAmbiguous Install Lifecycle Scriptpackage.json

MediumNetwork

MediumEnvironment Vars

MediumShips Build Helperscripts/pre-commit.sh

Affected versions and remediation

This report applies to @chem-x/create-chemx@26.9.16-1408.

See all versions of @chem-x/create-chemx for other recorded verdicts.

Avoid installing @chem-x/create-chemx@26.9.16-1408. Remove it from direct dependencies and check your lockfile for transitive copies.
Choose an independently verified alternative or release. This report does not establish that other versions are safe.
If this version ran, investigate the affected machine and build environment. Rotate credentials it could access and rebuild from a trusted environment.

Evidence last updated: 2026-10-12 06:04:18.807Z (UTC).

Think this verdict is wrong? Dispute it on GitHub or read how reports are produced.

AI Security Review

Decision evidence

Source & flagged code

Source & flagged code

Findings

Affected versions and remediation

Related packages

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Other AI-agent control-surface risk packages

Behavioral surface

Related packages

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Other AI-agent control-surface risk packages

Source & flagged code