frida-trick

My own collection of Frida script and tricks (Java / Native / TEE)

1. Scripts summary

1.a file_access.js ( do file descriptor lookup)

File : https://raw.githubusercontent.com/FrenchYeti/frida-trick/master/scripts/file_access.js

Observe file system accesses by hooking some java.io.File* classes and methods, libc open/read functions and try to resolve association between file descriptor and path. Optionally, it can dumps the data. The first block contains the configuration.

The following code extract explains how configure the script above.

var CONFIG = {
    // if TRUE enable data dump 
    printEnable: true,
    
    // if TRUE enable libc.so open/read/write hook
    printLibc: false,
    
    // if TRUE print the stack trace for each hook
    printStackTrace: false,
    
    // to filter the file path whose data want to be dumped in ASCII 
    dump_ascii_If_Path_contains: [".log", ".xml", ".prop"],
    
    // to filter the file path whose data want to be NOT dumped in hexdump (useful for big chunk and excessive reads) 
    dump_hex_If_Path_NOT_contains: [".png", "/proc/self/task", "/system/lib", "base.apk", "cacert"],
    
    // to filter the file path whose data want to be NOT dumped fron libc read/write (useful for big chunk and excessive reads) 
    dump_raw_If_Path_NOT_contains: [".png", "/proc/self/task", "/system/lib", "base.apk", "cacert"]
}

1.b log_to_file.py

File : https://raw.githubusercontent.com/FrenchYeti/frida-trick/master/scripts/log_to_file.py

It is an example of "how to log hook output into a file on host computer". You should edit file to adapt it to your case.

2. Tricks

2.a Generic tricks

Attach to a running process by name.

frida -U -p $(frida-ps -U | grep <appname> | tail -n 1 | cut -b1-5) -l <your_scripts>

2.b Java tricks

Print the stack trace if called from a Java Hook (see scripts/file_access.js script for example)

var JavaThread = Java.use("java.lang.Thread");
function printStackTrace(){
    var th = Java.cast( JavaThread.currentThread(), JavaThread);
    var stack = th.getStackTrace(), e=null;

    for(var i=0; i<stack.length; i++){
        console.log("\t"+stack[i].getClassName()+"."+stack[i].getMethodName()+"("+stack[i].getFileName()+")");
    }
}

2.c TEE tricks

To observe shared buffer, set the folder scripts/qsee as working directory and run frida-trace like below.

cd ./scripts/qsee
frida-trace -U -p $(frida-ps -U | grep system_server | cut -b1-5) -I "libQSEEComAPI.so"