A dual-purpose Chrome Extension:
- For everyday users: proactively disable Service Workers to improve browser performance, reduce tracking, and gain predictability.
- For Red Team operators and penetration testers: a tactical tool to neutralize client-side Service Worker defenses and expose hidden application logic.
Service Workers enable offline caching, push notifications, background sync, and request interception. While useful, they can lead to:
- Stale Content: Aggressive caching hides fresh content.
- Unwanted Notifications: Persistent prompts and background messages.
- Performance Overhead: Extra CPU and battery usage.
- Privacy Concerns: Silent background requests without user control.
- Security Barriers: Obfuscation of backend APIs and enforced client-side validation.
For power users, developers, and security professionals, controlling this layer is essential.
4ndr0serviceguard enforces a default-deny Service Worker policy, blocking all registrations globally unless explicitly allowed. The Ghost Protocol is a significant upgrade from the previous Nullifier Protocol, providing a much stealthier and more robust method of nullification.
- Everyday users get faster, cleaner, and more private browsing.
- Operators can surgically dismantle Service Worker protections, revealing hidden endpoints, bypassing client-side validation, and triggering legacy fallbacks.
This model delivers predictability, privacy, and expanded attack surface visibility.
- 🛡️ Ghost Protocol: Global kill switch for Service Workers using a stealthy proxy-based approach.
- ✍️ Intelligent Whitelist: Add trusted domains and their subdomains (e.g.,
google.comcoversdocs.google.com). - 🤫 Stealth API Nullification: Returns dynamic, convincing fake objects to avoid breakage or detection.
- ⚡ Instant Execution: Injected at
document_startbefore page scripts. - ✅ Live Validation: Input checked in real time via popup.
- ✨ Manifest V3: Modern, asynchronous, and secure codebase.
Additional operator-level traits:
- Surgical Target Enablement: Per-domain SW restoration.
- Zero-Day Race Condition Dominance: Guaranteed execution before target scripts.
- Customizable Source: No build step; edit scripts directly.
pacifier_v2.js injects into the MAIN world at document_start. It overwrites navigator.serviceWorker with a proxy that intercepts all property access and method calls. All registration attempts are intercepted and return a convincing, dynamically generated fake ServiceWorkerRegistration object.
background.js checks tab URLs against the whitelist. For trusted domains, it reinjects the original navigator.serviceWorker object, restoring full Service Worker functionality.
- Target:
secure-bank.comuses SW to add tokens or encrypt payloads. - Action: Do not whitelist. SW is nullified.
- Result: Intercept proxy sees raw API traffic. Test injection, tampering, bypasses.
2. De-cloaking Hidden Endpoints
- Target:
content-delivery.netproxies all API calls through SW. - Action: Disable SW.
- Result: App falls back to direct requests, exposing real backend URLs.
- Target:
shiny-app.iowith complex PWA logic. - Action: Nullify SW.
- Result: Legacy app path loads. Older vulnerabilities may be exposed.
Not on Chrome Web Store. Load manually:
git clone https://github.com/4ndr0666/4ndr0serviceguard.git- Go to
chrome://extensions. - Enable Developer mode.
- Click Load unpacked and select the repo folder.
- Extension icon appears in toolbar.
Click the icon to open control popup:
- Ghost Protocol Switch: Master on/off toggle.
- Whitelist Textarea: Add domains (one per line). Subdomains included automatically. Reload pages after edits.
- Default-deny applied immediately when extension is loaded.
- Use whitelist to scope Service Worker restoration during active engagements.
- Reload the target tab after whitelist changes.
- MAIN World Injection: Same privilege as site scripts.
- API Proxying: Overwrites
navigator.serviceWorkerwith a proxy object that intercepts all interactions. - Dynamic Mocking: Returns dynamically generated fake objects that are more convincing than static stubs.
- Surgical Restoration: Reinstate originals on whitelisted domains.
- No build process.
- Modify JS source directly to fit engagement needs.
- Reload via
chrome://extensionsafter editing.
PRs and issues are welcome. Bug fixes, new features, and operational improvements encouraged.
Licensed under the MIT License. See LICENSE.