@chem-x/create-chemx@26.9.20-408
Chemical X Protocol: Private drop-in architecture starter kit and capsule generator
AI Security Review
scanned 11d ago · by lpm-firewall-aiThe automatic postinstall mutates project and potentially global AI-agent control configuration to register an executable MCP server without asking the user. This meets the policy for blocking unconsented install-time agent control-surface mutation; the inspected code does not establish credential theft or an install-time network request.
Static reason
High-risk behavior combination matched malicious policy.; previous stored version diff introduced dangerous source
Trigger
Installing the package through npm, which runs its postinstall hook.
Impact
The package adds a server command to AI-agent configuration, enabling those agents to invoke the package’s MCP server.
Mechanism
The hook calls the MCP installer for the consumer directory. It writes MCP configuration files and, when Antigravity’s config directory exists, updates its global configuration and agent schemas.
Policy narrative
On npm installation, the postinstall hook runs the MCP installer against the consumer’s working directory. The installer adds a Chemical X server entry to Cursor and VS Code project configuration and may also update the user’s Antigravity configuration. These changes establish an AI-agent integration without a separate consent step.
AI rationale
The automatic postinstall mutates project and potentially global AI-agent control configuration to register an executable MCP server without asking the user. This meets the policy for blocking unconsented install-time agent control-surface mutation; the inspected code does not establish credential theft or an install-time network request.
Evidence
package.jsoncli/postinstall.jscli/mcp/installer.js.cursor/mcp.json.vscode/mcp.json~/.gemini/config/mcp_config.json
Decision evidence
public snapshotAI identified this as a dangerous AI-agent capability at 96.0% confidence with low false-positive risk.
Evidence for policy risk
- `package.json` defines a `postinstall` hook that runs `cli/postinstall.js`.
- The postinstall handler targets the consumer’s working directory and calls `installAllMcpConfigs` without a consent check.
- That installer writes MCP configuration into the consumer’s `.cursor/mcp.json` and `.vscode/mcp.json` files, registering the `chemical-x` server.
- When Antigravity’s config directory exists, the same installer also writes a global MCP entry and synchronizes agent schemas and instructions.
- The generated MCP command can fall back to `npx -y chemx mcp`, adding an executable agent integration during package installation.
Evidence against
- The package’s interactive installer presents MCP setup as a selectable option; that is separate from the automatic postinstall path.
- The inspected installer configures MCP command entries; this evidence does not establish credential theft or an install-time network request.
Behavioral surface
ChildProcessEnvironmentVarsFilesystemNetwork
Source & flagged code
11 flagged · loading sourcepackage.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 unpkgcli/errors/errors.spec.jsView file
27patternName = github_pat
severity = critical
line = 27
Critical
Critical Secret
Package contains a critical-looking secret pattern.
cli/errors/errors.spec.jsView on unpkg · L27Findings
3 Critical6 High5 Medium4 Low
CriticalCritical Secretcli/errors/errors.spec.js
CriticalAi Agent Control Hijackcli/mcp/installer.js
CriticalSecret Patterncli/errors/errors.spec.js
HighInstall Time Lifecycle Scriptspackage.json
HighChild Processcli/audit-preflight-git.js
HighShellcli/build/executor.js
HighSame File Env Network Executioncli/license.js
HighTrigger Reachable External Ai Agent Control Surface Mutationcli/scaffold.js
HighPrevious Version Dangerous Deltacli/license.js
MediumAmbiguous Install Lifecycle Scriptpackage.json
MediumNetwork
MediumEnvironment Vars
Affected versions and remediation
This report applies to @chem-x/create-chemx@26.9.20-408.
See all versions of @chem-x/create-chemx for other recorded verdicts.
- Avoid installing @chem-x/create-chemx@26.9.20-408. 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: .
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