Xposed模块开发：运行时修改技术

1. Xposed框架核心原理

1.1 运行时架构解析

Android ART Hook机制：

graph TD  A[目标APP进程] --> B{系统Zygote}  B -->|加载Xposed| C[XposedBridge]  C --> D[模块1]  C --> E[模块2]  D --> F[Hook目标方法]  E --> F

1.1.1 核心组件交互流程

XposedBridge：注入Zygote进程，管理模块生命周期
Xposed模块：声明assets/xposed_init入口，实现IXposedHookLoadPackage接口
Hook逻辑：通过XposedHelpers动态修改目标类方法

1.2 与Frida/Root方案对比

维度	Xposed	Frida	Root方案
侵入性	需修改系统	无	需解锁Bootloader
稳定性	高	依赖设备兼容性	高
实时生效	需重启APP	即时生效	即时生效
开发复杂度	Java/Kotlin为主	多语言支持	需Native开发

2. 开发环境配置

2.1 框架部署方案

Magisk + LSPosed安装流程：

# 通过Magisk安装LSPosed  
adb install Magisk-v26.4.apk  
adb push LSPosed-v1.9.2.zip /sdcard/  
# Magisk内刷入模块后重启

设备兼容性验证：

if (XposedBridge.isXposedEnabled()) {  Log.d("XposedCheck", "框架已激活");  
} else {  throw new RuntimeException("Xposed未启用");  
}

2.2 模块开发脚手架

build.gradle关键配置：

dependencies {  compileOnly 'de.robv.android.xposed:api:82'  compileOnly 'de.robv.android.xposed:api:82:sources'  
}  android {  defaultConfig {  // 声明Xposed模块标识  resValue "string", "xposed_module_id", "com.example.hookdemo"  resValue "bool", "xposed_description", "示例模块"  }  
}

xposed_init入口文件：

com.example.hookdemo.HookEntry

3. Hook技术深度实践

3.1 方法级拦截

基础Hook模板：

public class HookEntry implements IXposedHookLoadPackage {  @Override  public void handleLoadPackage(XC_LoadPackage.LoadPackageParam lpparam) {  if (!lpparam.packageName.equals("com.target.app")) return;  XposedHelpers.findAndHookMethod(  "com.target.app.MainActivity",  lpparam.classLoader,  "onCreate",  Bundle.class,  new XC_MethodHook() {  @Override  protected void beforeHookedMethod(MethodHookParam param) {  Log.d("Xposed", "MainActivity正在启动");  }  @Override  protected void afterHookedMethod(MethodHookParam param) {  TextView tv = ((Activity) param.thisObject).findViewById(R.id.text);  tv.setText("已被修改");  }  }  );  }  
}

3.2 构造函数Hook

修改单例实例：

XposedHelpers.findAndHookConstructor(  "com.target.app.Singleton",  lpparam.classLoader,  new XC_MethodHook() {  @Override  protected void afterHookedMethod(MethodHookParam param) {  // 替换单例实例  Field instanceField = param.thisObject.getClass().getDeclaredField("INSTANCE");  instanceField.setAccessible(true);  instanceField.set(null, new CustomSingleton());  }  }  
);

4. 资源篡改技术

4.1 布局动态修改

替换View内容：

XposedHelpers.findAndHookMethod(  "android.app.Activity",  lpparam.classLoader,  "setContentView",  int.class,  new XC_MethodHook() {  @Override  protected void afterHookedMethod(MethodHookParam param) {  Activity activity = (Activity) param.thisObject;  View rootView = activity.getWindow().getDecorView();  TextView target = rootView.findViewById(activity.getResources().getIdentifier("title", "id", activity.getPackageName()));  target.setText("Hacked Title");  }  }  
);

4.2 资源重定向

修改字符串资源：

<!-- 模块资源文件res/values/strings.xml -->  
<string name="original_text">New Content</string>

Hook资源加载：

XposedHelpers.findAndHookMethod(  "android.content.res.Resources",  lpparam.classLoader,  "getString",  int.class,  new XC_MethodHook() {  @Override  protected void beforeHookedMethod(MethodHookParam param) {  int id = (int) param.args[0];  if (id == R.string.original_text) {  param.setResult("已被修改");  }  }  }  
);

5. 反检测对抗技术

5.1 隐藏Xposed特征

绕过Xposed检测：

XposedHelpers.findAndHookMethod(  "android.os.SystemProperties",  lpparam.classLoader,  "get",  String.class,  new XC_MethodHook() {  @Override  protected void beforeHookedMethod(MethodHookParam param) {  if ("ro.xposed".equals(param.args[0])) {  param.setResult(""); // 清空特征值  }  }  }  
);

5.2 动态代码加载

解密关键逻辑：

// 动态加载解密后的类  
byte[] decrypted = decrypt(hiddenData);  
Class<?> realClass = (Class<?>) XposedHelpers.callMethod(  ClassLoader.getSystemClassLoader(),  "defineClass",  decrypted,  0,  decrypted.length  
);

6. 企业级实战案例

6.1 协议签名绕过

Hook签名算法：

XposedHelpers.findAndHookMethod(  "com.target.app.SignUtils",  lpparam.classLoader,  "generateSign",  String.class,  new XC_MethodHook() {  @Override  protected void beforeHookedMethod(MethodHookParam param) {  param.args[0] = "fixed_signature"; // 固定签名值  }  }  
);

6.2 权限提升攻击

动态添加权限：

XposedHelpers.findAndHookMethod(  "android.app.ContextImpl",  lpparam.classLoader,  "checkPermission",  String.class,  int.class,  int.class,  new XC_MethodHook() {  @Override  protected void beforeHookedMethod(MethodHookParam param) {  if (Manifest.permission.READ_SMS.equals(param.args[0])) {  param.setResult(PackageManager.PERMISSION_GRANTED);  }  }  }  
);

7. 模块调试与优化

7.1 日志实时监控

跨进程日志收集：

XposedBridge.log("Hook事件: " + param.method.getName());  // 通过Socket转发到PC  
Socket client = new Socket("192.168.1.100", 9000);  
PrintWriter out = new PrintWriter(client.getOutputStream());  
out.println("HOOK_LOG: " + logMsg);

7.2 性能优化策略

Hook过滤器：

public void handleLoadPackage(XC_LoadPackage.LoadPackageParam lpparam) {  Set<String> targetClasses = new HashSet<>(Arrays.asList(  "com.target.app.MainActivity",  "com.target.app.network.ApiService"  ));  XposedHelpers.findAndHookMethod(  lpparam.classLoader,  targetClasses,  "onCreate",  Bundle.class,  new XC_MethodHook() { /* ... */ }  );  
}

技术验证清单：