Frida Tutorial 3

Learn & practice AWS Hacking:HackTricks Training AWS Red Team Expert (ARTE) Learn & practice GCP Hacking: HackTricks Training GCP Red Team Expert (GRTE)

Support HackTricks

• Check the subscription plans!

• Join the 💬 Discord group or the telegram group or follow us on Twitter 🐦 @hacktricks_live.

• Share hacking tricks by submitting PRs to the HackTricks and HackTricks Cloud github repos.

Bug bounty tip: regístrate en Intigriti, una plataforma de recompensas por errores premium creada por hackers, para hackers! Únete a nosotros en https://go.intigriti.com/hacktricks hoy, y comienza a ganar recompensas de hasta $100,000!

Register - IntigritiRegister - Intigriti

---

Este es un resumen de la publicación: https://joshspicer.com/android-frida-1 APK: https://github.com/OWASP/owasp-mstg/blob/master/Crackmes/Android/Level_01/UnCrackable-Level1.apk

Solution 1

Basado en https://joshspicer.com/android-frida-1

Hook the _exit()_ function and decrypt function so it print the flag in frida console when you press verify:

Java.perform(function () {
send("Starting hooks OWASP uncrackable1...");

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 : " + getString(ret));

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

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  :)");
};

send("Hooks installed.");
});

Solución 2

Basado en https://joshspicer.com/android-frida-1

Enganchar rootchecks y la función de desencriptación para que imprima la bandera en la consola de frida cuando presiones verificar:

Java.perform(function () {
send("Starting hooks OWASP uncrackable1...");

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 : " + getString(ret));

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

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

var rootcheck2 = Java.use("sg.vantagepoint.a.c");
rootcheck2.b.overload().implementation = function() {
send("sg.vantagepoint.a.c.b()Z  Root check 2 HIT!  test-keys");
return false;
};

var rootcheck3 = Java.use("sg.vantagepoint.a.c");
rootcheck3.c.overload().implementation = function() {
send("sg.vantagepoint.a.c.c()Z  Root check 3 HIT!  Root packages");
return false;
};

var debugcheck = Java.use("sg.vantagepoint.a.b");
debugcheck.a.overload("android.content.Context").implementation = function(var_0) {
send("sg.vantagepoint.a.b.a(Landroid/content/Context;)Z  Debug check HIT! ");
return false;
};

send("Hooks installed.");
});

Consejo de bug bounty: regístrate en Intigriti, una plataforma de bug bounty premium creada por hackers, para hackers! Únete a nosotros en https://go.intigriti.com/hacktricks hoy, y comienza a ganar recompensas de hasta $100,000!

Register - IntigritiRegister - Intigriti

Aprende y practica Hacking en AWS:HackTricks Training AWS Red Team Expert (ARTE) Aprende y practica Hacking en GCP: HackTricks Training GCP Red Team Expert (GRTE)

Apoya a HackTricks

• Revisa los planes de suscripción!

• Únete al 💬 grupo de Discord o al grupo de telegram o síguenos en Twitter 🐦 @hacktricks_live.

• Comparte trucos de hacking enviando PRs a los HackTricks y HackTricks Cloud repositorios de github.