appdbg: A virtual machine disguised as a debugger

1. Objectives

Today’s apps are restless. The Java layer tries to flirt with the Native layer, and the Native layer likes to collude with Jave.

It’s too difficult to analyze a so quietly.

Is it possible to simulate the execution of the App on the PC, so that when Native is connected to the Jave layer, a lot of work of supplementing the environment can be saved?

appdbg is such a virtual machine disguised as a debugger.

Teach you how to build a Frida + Sekiro RPC framework

Objectives

Signing with a mobile phone is a tricky solution. We have introduced it before.

Sekiro + Xposed signature solution

Frida is now widely used, and Sekiro has also upgraded to a new version. Today we will teach you how to build a Frida + Sekiro Rpc framework.

Run the server first

The official website is here https://github.com/virjar/sekiro

git clone it;

On Linux or Mac, execute the script build_demo_server.sh, and then get the release compressed package: sekiro-service-demo/target/sekiro-release-demo.zip

An e-commerce App sign algorithm upgrade verification

1. Objectives

The app has been upgraded, but has its algorithm also been upgraded? This is a question. We need to verify it quickly, otherwise Mr. Li will go crazy.

Note:
  • Objection
  • Unidbg
  • gettimeofday
  • lrand48
  • V9.4.2

2. Analysis

In the previous analysis of a signature algorithm of an e-commerce app (Part 1) we located the com.xxxxxxxx.common.utils.BitmapkitUtils class and its getSignFromJni function as the key functions for calculating the sign.

In the new version, we first use Objection to hook com.xxxxxxxx.common.utils.BitmapkitUtils

Code Restoration Technology ARM Assembly Introduction Tutorial (I) Hello World!

1. Objectives

  • Why learn ARM assembly?

No reason.

  • Is it useful to learn ARM assembly?

It’s useless

  • Can I find a job after learning ARM assembly?

None of the popular large-scale software is written in assembly language, so what do you think?

  • Do you still need to learn ARM assembly?

Why not learn it? You have nothing to do anyway. Knowing some low-level languages and getting close to the essence of computer operation is still very cool.

Iphone Jailbreak 2020

1. Objectives

Note:
  • iOS jailbreak
  • MacOS Mojave 10.14.6
  • Xcode Version 11.3.1

I was planning to build a framework for app signature calculation based on iOS, but I found that the system of my test phone iPhone 11.2.2 could not be jailbroken. A lot of xx assistants’ corporate signatures have expired, so I couldn’t install jailbreak software. Fortunately, I had used Cydia Impactor to do self-signing before, so I continued to use it, and the result was: