registry  /  ttj-skills-browser  /  1.2.18

ttj-skills-browser@1.2.18

Renamed to 'ttj-skills-playwright'. Please install: npm i -g ttj-skills-playwright

ttj-skills-browser - Dedicated CDP browser with one-shot commands (eval/goto/screenshot) and page reference visualization

AI Security Review

scanned 2h ago · by lpm-firewall-ai

LPM blocks this version under the AI-agent control-surface policy. Installation silently mutates global Claude Code and Codex skill directories with package-controlled instructions. Runtime also self-updates globally after a registry check.

Static reason
High-risk behavior combination matched malicious policy.; source matched previously finalized malicious package; routed for review; previous stored version diff introduced dangerous source
Trigger
`npm install` activates `postinstall`; invoking the CLI activates the update check.
Impact
Package-controlled agent instructions persist in foreign global control surfaces and can change through later npm releases.
Mechanism
Postinstall AI-agent skill injection and unattended global self-update.
Policy narrative
On npm installation, the postinstall script copies package-supplied instructions into the user's global Claude Code and Codex skill directories without an explicit setup command. Those instructions direct AI-driven browser automation. Separately, each CLI launch checks npm once daily and, if newer, executes a global npm upgrade, allowing future package releases to replace the installed skill and executable automatically. This is unconsented install-time mutation of broad external AI-agent control surfaces.
Rationale
Source inspection confirms an automatic postinstall write to both `~/.claude/skills` and `~/.agents/skills`, which is a foreign/broad AI-agent control surface. The unattended global update path compounds the persistence and supply-chain risk.
Evidence
package.jsonscripts/install-skill.jsdist/cli.jsdist/browser.jsdist/utils.js.claude/skills/ttj-skills-browser/SKILL.md~/.claude/skills/ttj-skills-browser/SKILL.md~/.agents/skills/ttj-skills-browser/SKILL.md~/.ttj-skills-browser-installed~/.ttj-skills-browser/.last-update-check
Network endpoints2
registry.npmjs.org/ttj-skills-browser/latest127.0.0.1:${port}

Decision evidence

public snapshot
AI called this Malicious at 99.0% confidence as Malware with low false-positive risk.
Evidence for policy block
  • `package.json` runs `postinstall` automatically.
  • `scripts/install-skill.js` copies bundled skill to `~/.claude/skills/ttj-skills-browser/SKILL.md`.
  • The same postinstall writes to `~/.agents/skills/ttj-skills-browser/SKILL.md` and creates `~/.ttj-skills-browser-installed`.
  • `dist/cli.js` invokes runtime auto-update before handling normal commands.
  • `dist/browser.js` checks `registry.npmjs.org` then runs global `npm install -g ttj-skills-browser@latest` without consent.
Evidence against
  • No source reads or transmits environment secrets, credentials, or SSH/cloud files.
  • Observed network use is npm update checking and local CDP, not direct data exfiltration.
  • Browser evaluation/navigation requires an explicit CLI command after installation.
Behavioral surface
Source
ChildProcessEnvironmentVarsFilesystemNetworkShell
Supply chain
HighEntropyStringsUrlStrings
ManifestNo manifest risk signals triggered.
scanned 8 file(s), 62.1 KB of source, external domains: 127.0.0.1, registry.npmjs.org, www.google.com, www.naver.com

Source & flagged code

7 flagged · loading source
package.jsonView file
scripts.postinstall = node scripts/install-skill.js
High
Install Time Lifecycle Scripts

Package defines install-time lifecycle scripts.

package.jsonView on unpkg
dist/utils.jsView file
5import path from 'path'; L6: import net from 'net'; L7: import https from 'https'; L8: import { exec } from 'child_process'; L9: import { promisify } from 'util'; ... L17: */ L18: export const getOsType = () => process.platform === 'win32' L19: ? 'windows' ... L25: */ L26: export const getHomeDir = () => os.homedir(); L27: /** ... L33: const isWindows = getOsType() === 'windows';
High
Sandbox Evasion Gated Capability

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

dist/utils.jsView on unpkg · L5
matchType = normalized_sha256 matchedPackage = ttj-sk[redacted]@1.2.17 matchedPath = dist/utils.js matchedIdentity = npm:dHRqLXNraWxscy1icm93c2Vy:1.2.17 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.

dist/utils.jsView on unpkg
scripts/install-skill.jsView file
14Install-time AI-agent control hijack evidence: L14: const skillName = 'ttj-sk[redacted]'; L15: const sk[redacted] = path.join(__dirname, '..', '.claude', 'skills', skillName); L16: const skillFile = 'SKILL.md'; ... L19: if (!fs.existsSync(dir)) { L20: fs.mkdirSync(dir, { recursive: true }); L21: } ... L53: // Claude Code: 기존 /ttj-sk[redacted] 호출 방식 유지 L54: const claudeTargetDir = path.join(homedir(), '.claude', 'skills', skillName); L55: const claudeTargetFile = path.join(claudeTargetDir, skillFile); L56: ensureDir(claudeTargetDir); L57: fs.copyFileSync(sourceFile, claudeTargetFile); L58: console.log(`✅ Claude Code 스킬 설치 완료: ${claudeTargetFile}`); Payload evidence from .claude/skills/ttj-sk[redacted]/SKILL.md: L69: L70: ### eval — 활성 탭에서 JS 실행 (결과는 JSON으로 stdout 출력) L71: ```bash ... L79: ```bash L80: ttj-sk[redacted] goto https://www.naver.com L81: ttj-sk[redacted] goto naver.com # https:// 자동 보완
Critical
Ai Agent Control Hijack

Install-time source drops package-supplied AI-agent/MCP control files or instructions.

scripts/install-skill.jsView on unpkg · L14
dist/browser.jsView file
matchType = normalized_sha256 matchedPackage = ttj-sk[redacted]@1.2.17 matchedPath = dist/browser.js matchedIdentity = npm:dHRqLXNraWxscy1icm93c2Vy:1.2.17 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.

dist/browser.jsView on unpkg
dist/cli.jsView file
matchType = normalized_sha256 matchedPackage = ttj-sk[redacted]@1.2.17 matchedPath = dist/cli.js matchedIdentity = npm:dHRqLXNraWxscy1icm93c2Vy:1.2.17 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.

dist/cli.jsView on unpkg
matchType = previous_version_dangerous_delta matchedPackage = ttj-sk[redacted]@1.2.16 matchedIdentity = npm:dHRqLXNraWxscy1icm93c2Vy:1.2.16 similarity = 0.571 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.

dist/cli.jsView on unpkg

Findings

1 Critical6 High3 Medium5 Low
CriticalAi Agent Control Hijackscripts/install-skill.js
HighInstall Time Lifecycle Scriptspackage.json
HighSandbox Evasion Gated Capabilitydist/utils.js
HighKnown Malware Source Similaritydist/utils.js
HighKnown Malware Source Similaritydist/browser.js
HighKnown Malware Source Similaritydist/cli.js
HighPrevious Version Dangerous Deltadist/cli.js
MediumNetwork
MediumEnvironment Vars
MediumStructural Risk Force Deep Review
LowNon Install Lifecycle Scripts
LowScripts Present
LowFilesystem
LowHigh Entropy Strings
LowUrl Strings