# How reverse-skill Handles Dynamic Analysis of Android Applications Using Frida

> Discover how reverse-skill automates dynamic analysis of Android apps with Frida. Explore its routing system, PowerShell runner, and documented hook patterns for runtime inspection.

- Repository: [ZhaoXu/reverse-skill](https://github.com/zhaoxuya520/reverse-skill)
- Tags: how-to-guide
- Published: 2026-08-25

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**The reverse-skill framework automates Frida-based dynamic analysis through a routing system that maps APK tasks to the `apk-reverse` skill, providing a PowerShell runner script and documented hook patterns for runtime inspection.**

Android reverse engineering often requires both static and dynamic techniques. The **reverse-skill** repository by zhaoxuya520 implements a structured workflow where **Frida** serves as the primary dynamic instrumentation engine for analyzing running Android applications. This article explains how the framework orchestrates Frida operations, from tool discovery to script injection.

## Routing System for Android APK Analysis

The framework's entry point for any Android-related task is a centralized routing mechanism.

In [`skills/config/routing.json`](https://github.com/zhaoxuya520/reverse-skill/blob/main/skills/config/routing.json), the system maps the *APK / Android app* hint to the **apk-reverse** skill. This routing decision triggers the entire Android-specific toolchain, including Frida integration. The routing table ensures that analysts never manually configure tool selection—the framework infers the correct skill based on input file type.

```json
// Conceptual excerpt from skills/config/routing.json
{
  "pattern": "*.apk",
  "skill": "apk-reverse",
  "tools": ["frida", "jadx", "apktool"]
}

```

Tool discovery happens through `skills/scripts/lib/ToolDiscovery.ps1`, which registers Frida with purpose **'Frida 动态注入'** (Frida dynamic injection) and links the executable to the runner helper.

## The Frida Runner: frida-run.ps1

The PowerShell script at `apk-reverse/scripts/frida-run.ps1` is the unified CLI entry point for all Frida operations. It wraps the native Frida CLI (`frida`, `frida-ps`) and exposes convenience parameters for common workflows.

### Device and Process Enumeration

Before attaching to a target, analysts enumerate available devices and running processes:

```powershell

# List connected devices

pwsh -File "C:\reverse-skill\apk-reverse\scripts\frida-run.ps1" -ListDevices

# List processes on USB-connected device

pwsh -File "C:\reverse-skill\apk-reverse\scripts\frida-run.ps1" -Usb -ListProcesses

```

### Application Spawning and Script Injection

The `-Spawn` parameter launches an application in a suspended state, attaches the Frida injector, then resumes execution with the specified JavaScript hook loaded:

```powershell
pwsh -File "C:\reverse-skill\apk-reverse\scripts\frida-run.ps1" `
    -Usb `
    -Spawn `
    -Package com.example.myapp `
    -ScriptPath "C:\hooks\sslPinBypass.js"

```

Key parameters include:

- `-Usb` – Target USB-connected devices (typical for physical Android phones)
- `-Spawn` – Start the application fresh rather than attaching to a running instance
- `-Package` – Specify the target application's package name
- `-ScriptPath` – Path to the JavaScript hook file

The script internally forwards these arguments to `frida -U -f <pkg> -l <script>`, providing a consistent PowerShell-native interface.

## Hook Patterns and Anti-Debug Techniques

The framework's documentation in [`skills/reverse-engineering/tools-dynamic.md`](https://github.com/zhaoxuya520/reverse-skill/blob/main/skills/reverse-engineering/tools-dynamic.md) catalogs common Frida patterns for Android analysis. Two fundamental interception mechanisms are emphasized:

### Interceptor.attach for Method Tracing

Use `Interceptor.attach` to observe function entry and exit without altering behavior:

```javascript
Interceptor.attach(Module.findExportByName(null, "strcmp"), {
    onEnter: function(args) {
        console.log("[strcmp] comparing:", args[0].readCString(), "vs", args[1].readCString());
    }
});

```

### Interceptor.replace for Runtime Patching

Use `Interceptor.replace` to substitute entire function implementations, effective for bypassing security controls:

```javascript
Java.perform(() => {
    const CertificatePinner = Java.use('okhttp3.CertificatePinner');
    CertificatePinner.check.overload('java.lang.String', 'java.security.cert.Certificate').implementation = function(host, cert) {
        console.log('[+] SSL pinning bypassed for', host);
        // Accept any certificate by doing nothing
    };
});

```

This pattern targets OkHttp's certificate pinning—common in modern Android applications—and demonstrates how reverse-skill enables real-time verification of static analysis hypotheses.

## Integration with Static Analysis Workflow

The framework bridges static and dynamic phases through skill composition. When an APK contains native `.so` libraries:

1. **Static phase** – `jadx` or `apktool` decompiles Dalvik bytecode; **radare2** or **ida-reverse** skills analyze native libraries
2. **Hypothesis formation** – Analysts identify candidate functions (e.g., `strcmp` comparisons for license checks, `memcmp` for cryptographic validation)
3. **Dynamic validation** – The `frida-run.ps1` script injects hooks to confirm control flow and extract runtime values

This pivot from static to dynamic is automated through the routing layer—no manual path configuration required.

## Pipeline Automation

Environment setup is handled by [`skills/scripts/refresh-tool-index.sh`](https://github.com/zhaoxuya520/reverse-skill/blob/main/skills/scripts/refresh-tool-index.sh), which:

- Detects Frida installation on the system
- Adds Frida to the skill's tool index with version metadata
- Ensures the `frida-run.ps1` script paths are correctly resolved

Running this script prepares any CI/CD or analysis workstation for immediate Frida operations.

## Summary

- **Routing** – [`skills/config/routing.json`](https://github.com/zhaoxuya520/reverse-skill/blob/main/skills/config/routing.json) automatically directs APK files to the `apk-reverse` skill
- **Tool registration** – `ToolDiscovery.ps1` identifies Frida as a dynamic injection capability
- **Execution wrapper** – `frida-run.ps1` provides unified PowerShell access to device listing, process enumeration, spawning, and script injection
- **Documentation** – [`tools-dynamic.md`](https://github.com/zhaoxuya520/reverse-skill/blob/main/tools-dynamic.md) contains authoritative hook patterns for Android-specific scenarios
- **Automation** – [`refresh-tool-index.sh`](https://github.com/zhaoxuya520/reverse-skill/blob/main/refresh-tool-index.sh) maintains environment readiness

## Frequently Asked Questions

### What Frida commands does reverse-skill support through its PowerShell wrapper?

The `frida-run.ps1` script supports device enumeration (`-ListDevices`), process listing (`-ListProcesses`), application spawning (`-Spawn -Package`), and custom script injection (`-ScriptPath`). It translates these parameters to native `frida` and `frida-ps` CLI invocations.

### How does reverse-skill choose when to use Frida versus static tools?

The routing table in [`skills/config/routing.json`](https://github.com/zhaoxuya520/reverse-skill/blob/main/skills/config/routing.json) maps file patterns to skills. APK files route to `apk-reverse`, which includes both static tools (JADX, apktool) and dynamic tools (Frida). Analysts explicitly invoke the Frida runner when runtime inspection is required.

### Can reverse-skill Frida hooks target specific Android versions or emulators?

Yes. The `frida-run.ps1` script accepts `-Usb` for physical devices and can target emulators or remote Frida-server instances through additional parameter combinations documented in [`tools-dynamic.md`](https://github.com/zhaoxuya520/reverse-skill/blob/main/tools-dynamic.md).

### Where are example Frida scripts for common Android bypasses documented?

The markdown file [`skills/reverse-engineering/tools-dynamic.md`](https://github.com/zhaoxuya520/reverse-skill/blob/main/skills/reverse-engineering/tools-dynamic.md) contains patterns for SSL pinning bypass, anti-debug circumvention, and memory scanning, with JavaScript implementations targeting Android-specific frameworks like OkHttp.