hacktricks/src/mobile-pentesting/android-app-pentesting/frida-tutorial

Frida Mafunzo

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Usakinishaji

Sakinisha frida tools:

pip install frida-tools
pip install frida

Pakua na sakinisha kwenye Android frida server (Download the latest release).
Mstari mmoja wa amri ili kuwasha upya adb katika root mode, kuungana nayo, kupakia frida-server, kumpa exec permissions na kuikimbiza kwenye background:

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 &"

Angalia ikiwa inafanya kazi:

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

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

Njia mbili za kawaida za ku-instrument apps za Android kwa kutumia Frida:

• Frida server (rooted devices): Pusha na endesha daemon ya native inayokuwezesha kuungana na mchakato wowote.
• Frida Gadget (no root): Weka Frida kama shared library ndani ya APK na ui-pakie kiotomatiki ndani ya mchakato lengwa.

Frida server (rooted)

# 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. Fungua APK, ongeza gadget .so na config:

• Weka libfrida-gadget.so ndani ya lib// (e.g., lib/arm64-v8a/)
• Unda assets/frida-gadget.config na mipangilio ya upakiaji ya script yako

Mfano wa frida-gadget.config

{
"interaction": { "type": "script", "path": "/sdcard/ssl-bypass.js" },
"runtime": { "logFile": "/sdcard/frida-gadget.log" }
}

2. Rejea/pakia gadget ili ianzishwe mapema:

• Rahisi zaidi: Ongeza stub ndogo ya Java kwa System.loadLibrary("frida-gadget") katika Application.onCreate(), au tumia kupakia maktaba ya native iliyopo.

3. Rudisha kifurushi na kusaini APK, kisha sakinisha:

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

4. Unganisha kutoka host kwenye mchakato wa gadget:

frida-ps -Uai
frida -U -n com.example.app

Notes

• Gadget inatambuliwa na baadhi ya hatua za ulinzi; hifadhi names/paths kwa utulivu na ziweke kuchelewa/tu kwa masharti ikiwa inahitajika.
• Kwa hardened apps, pendelea testing ya rooted ikitumia server + late attach, au ichanganye na kujificha kwa Magisk/Zygisk hiding.

Mafunzo

Mafunzo 1

Chanzo: https://medium.com/infosec-adventures/introduction-to-frida-5a3f51595ca1
APK: https://github.com/t0thkr1s/frida-demo/releases
Msimbo wa Chanzo: https://github.com/t0thkr1s/frida-demo

Soma kupitia kiungo.

Mafunzo 2

Chanzo: https://11x256.github.io/Frida-hooking-android-part-2/ (Sehemu 2, 3 & 4)
APKs na msimbo wa chanzo: https://github.com/11x256/frida-android-examples

Soma kupitia kiungo.

Mafunzo 3

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

Soma kupitia kiungo.

Unaweza kupata skripti zaidi za Awesome Frida hapa: https://codeshare.frida.re/

Mifano ya Haraka

Kuitisha Frida kutoka command line

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.

Skripti ya Msingi ya 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 functions bila vigezo

Hook kazi a() ya darasa sg.vantagepoint.a.c

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;
};
});

Hook java exit()

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()

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 .onCreate()

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 functions zenye parameters na kupata thamani

Hooking decryption function. Chapisha input, itisha original function ili decrypt input, na hatimaye chapisha data wazi:

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 functions na kuziita kwa pembejeo zetu

Hook function inayopokea string na uiite na string nyingine (kutoka here)

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
}

Getting an already created object of a class

Ikiwa unataka kuchota sifa fulani ya object iliyoundwa unaweza kutumia hii.

Katika mfano huu utaona jinsi ya kupata object ya darasa my_activity na jinsi ya kuita function .secret() ambayo itachapisha sifa ya kibinafsi ya object:

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 () {},
})

Mafunzo mengine ya Frida

• https://github.com/DERE-ad2001/Frida-Labs
• Part 1 of Advanced Frida Usage blog series: IOS Encryption Libraries

Marejeo

• Build a Repeatable Android Bug Bounty Lab: Emulator vs Magisk, Burp, Frida, and Medusa
• Frida Gadget documentation
• Frida releases (server binaries)

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