Frida 教程

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安装

安装 frida tools:

bash
pip install frida-tools
pip install frida

下载并安装 在 android 上 frida server (Download the latest release).
用于重启 adb 到 root 模式、连接到设备、上传 frida-server、赋予 exec 权限并在后台运行的一行命令:

bash
adb root; adb connect localhost:6000; sleep 1; adb push frida-server /data/local/tmp/; adb shell "chmod 755 /data/local/tmp/frida-server"; adb shell "/data/local/tmp/frida-server &"

检查 它是否 正常工作

bash
frida-ps -U #List packages and processes
frida-ps -U | grep -i <part_of_the_package_name> #Get all the package name

Frida server 与 Gadget (root vs. no-root)

使用 Frida 对 Android 应用进行插装的两种常见方法:

  • Frida server (rooted devices): 将一个本地守护进程推送并运行,使你可以附加到任意进程。
  • Frida Gadget (no root): 将 Frida 作为共享库捆绑到 APK 内,并在目标进程中自动加载它。

Frida server (rooted)

bash
# Download the matching frida-server binary for your device's arch
# https://github.com/frida/frida/releases
adb root
adb push frida-server-<ver>-android-<arch> /data/local/tmp/frida-server
adb shell chmod 755 /data/local/tmp/frida-server
adb shell /data/local/tmp/frida-server &    # run at boot via init/magisk if desired

# From host, list processes and attach
frida-ps -Uai
frida -U -n com.example.app

Frida Gadget (no-root)

  1. 解包 APK,添加 gadget .so 和配置:
  • 将 libfrida-gadget.so 放入 lib//(例如 lib/arm64-v8a/)
  • 创建 assets/frida-gadget.config,包含你用于加载脚本的设置

示例 frida-gadget.config

json
{
"interaction": { "type": "script", "path": "/sdcard/ssl-bypass.js" },
"runtime": { "logFile": "/sdcard/frida-gadget.log" }
}
  1. 引用/加载 gadget 以便它尽早被初始化:
  • 最简单:在 Application.onCreate() 中添加一个小的 Java stub,调用 System.loadLibrary("frida-gadget"),或者使用已存在的 native lib loading。
  1. 重新打包并签名 APK,然后安装:
bash
apktool d app.apk -o app_m
# ... add gadget .so and config ...
apktool b app_m -o app_gadget.apk
uber-apk-signer -a app_gadget.apk -o out_signed
adb install -r out_signed/app_gadget-aligned-debugSigned.apk
  1. 从主机附加到 gadget 进程:
bash
frida-ps -Uai
frida -U -n com.example.app

注意

  • Gadget 会被某些防护检测到;如有必要,请保持 名称/路径 隐蔽,并在加载时延后或按条件加载。
  • 对于加固的 apps,优先使用 rooted testing with server + late attach,或与 Magisk/Zygisk hiding 结合使用。

教程

Tutorial 1

From: https://medium.com/infosec-adventures/introduction-to-frida-5a3f51595ca1
APK: https://github.com/t0thkr1s/frida-demo/releases
Source Code: https://github.com/t0thkr1s/frida-demo

参见 link to read it.

Tutorial 2

From: https://11x256.github.io/Frida-hooking-android-part-2/ (Parts 2, 3 & 4)
APKs and Source code: https://github.com/11x256/frida-android-examples

参见 link to read it.

Tutorial 3

From: https://joshspicer.com/android-frida-1
APK: https://github.com/OWASP/owasp-mstg/blob/master/Crackmes/Android/Level_01/UnCrackable-Level1.apk

参见 link to read it.

You can find more Awesome Frida scripts here: https://codeshare.frida.re/

快速示例

Calling Frida from command line

bash
frida-ps -U

#Basic frida hooking
frida -l disableRoot.js -f owasp.mstg.uncrackable1

#Hooking before starting the app
frida -U --no-pause -l disableRoot.js -f owasp.mstg.uncrackable1
#The --no-pause and -f options allow the app to be spawned automatically,
#frozen so that the instrumentation can occur, and the automatically
#continue execution with our modified code.

基本 Python 脚本

python
import frida, sys

jscode = open(sys.argv[0]).read()
process = frida.get_usb_device().attach('infosecadventures.fridademo')
script = process.create_script(jscode)
print('[ * ] Running Frida Demo application')
script.load()
sys.stdin.read()

Hooking 无参数函数

Hook 类 sg.vantagepoint.a.c 的函数 a()

javascript
Java.perform(function () {
;  rootcheck1.a.overload().implementation = function() {
rootcheck1.a.overload().implementation = function() {
send("sg.vantagepoint.a.c.a()Z   Root check 1 HIT!  su.exists()");
return false;
};
});

拦截 java exit()

javascript
var sysexit = Java.use("java.lang.System")
sysexit.exit.overload("int").implementation = function (var_0) {
send("java.lang.System.exit(I)V  // We avoid exiting the application  :)")
}

Hook MainActivity .onStart() & .onCreate()

javascript
var mainactivity = Java.use("sg.vantagepoint.uncrackable1.MainActivity")
mainactivity.onStart.overload().implementation = function () {
send("MainActivity.onStart() HIT!!!")
var ret = this.onStart.overload().call(this)
}
mainactivity.onCreate.overload("android.os.Bundle").implementation = function (
var_0
) {
send("MainActivity.onCreate() HIT!!!")
var ret = this.onCreate.overload("android.os.Bundle").call(this, var_0)
}

Hook android 的 .onCreate()

javascript
var activity = Java.use("android.app.Activity")
activity.onCreate.overload("android.os.Bundle").implementation = function (
var_0
) {
send("Activity HIT!!!")
var ret = this.onCreate.overload("android.os.Bundle").call(this, var_0)
}

Hooking 带参数的函数并获取返回值

Hooking a decryption function。打印输入,调用原始函数 decrypt 输入,并最后打印明文数据:

javascript
function getString(data) {
var ret = ""
for (var i = 0; i < data.length; i++) {
ret += data[i].toString()
}
return ret
}
var aes_decrypt = Java.use("sg.vantagepoint.a.a")
aes_decrypt.a.overload("[B", "[B").implementation = function (var_0, var_1) {
send("sg.vantagepoint.a.a.a([B[B)[B   doFinal(enc)  // AES/ECB/PKCS7Padding")
send("Key       : " + getString(var_0))
send("Encrypted : " + getString(var_1))
var ret = this.a.overload("[B", "[B").call(this, var_0, var_1)
send("Decrypted : " + ret)

var flag = ""
for (var i = 0; i < ret.length; i++) {
flag += String.fromCharCode(ret[i])
}
send("Decrypted flag: " + flag)
return ret //[B
}

Hooking 函数并使用我们的输入调用它们

Hook 一个接收 string 的函数,并用另一个 string 调用它(来自 here

javascript
var string_class = Java.use("java.lang.String") // get a JS wrapper for java's String class

my_class.fun.overload("java.lang.String").implementation = function (x) {
//hooking the new function
var my_string = string_class.$new("My TeSt String#####") //creating a new String by using `new` operator
console.log("Original arg: " + x)
var ret = this.fun(my_string) // calling the original function with the new String, and putting its return value in ret variable
console.log("Return value: " + ret)
return ret
}

获取已创建的类对象

如果你想提取已创建对象的某个属性,可以使用下面的方法。

在这个示例中,你将看到如何获取类 my_activity 的对象以及如何调用函数 .secret() 来打印该对象的私有属性:

javascript
Java.choose("com.example.a11x256.frida_test.my_activity", {
onMatch: function (instance) {
//This function will be called for every instance found by frida
console.log("Found instance: " + instance)
console.log("Result of secret func: " + instance.secret())
},
onComplete: function () {},
})

其他 Frida 教程

参考资料

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