Skip to main content

Egg Hunter Shellcode x86 - SLAE Assignment 0x3

Before we start , I would like to bring your attention to this SLAE course from securitytube which will help you learn Shellcoding -

1. Introduction to Egg Hunter
2. Dummy Algo of Egg Hunter
3. Writing Egg Hunter Shellcode
4. Wrapper Script to generate shellcode with custom EGG tag

1. Introduction to Egg Hunters

Egg Hunter
Fuzzysecurity says :
The egg hunter is composed of a set of programmatic instructions that are translated to opcode and in that respect it is no different than any other shellcode (this is important because it might also contain badcharacters!!). The purpose of an egg hunter is to search the entire memory range (stack/heap/..) for our final stage shellcode and redirect execution flow to it.
After reading a lot of blog post I found this common paper link so thought of going through it.The paper contains very good information and different methods of egg hunting . I found sigaction method easy but every method has their own pros and cons. 
Please read this paper if you are interested in egg hunter's use/implementation.

2. Dummy Algo of Egg Hunter

if (value(addr)==EGGTAG/STRING)then
jmp to addr

3. Writing Egg Hunter Shellcode

4. Wrapper Script to generate custom TAG shellcode
Reverse TAG/EGG python program -

Final Script -

[x] C code here -
[x] egghunter.nasm - [32 bytes]
[x] Wrapper Script to generate egg hunter with custom tag can be found here -
[x] All scripts can be found here -
Proof of Concept :

This blog post has been created for completing the requirements of the SecurityTube Linux Assembly Expert certification: 
Student-ID: SLAE-1219


Popular posts from this blog

Review of Pentester Academy - Attacking and Defending Active Directory Lab

Few months ago I didn't know what Active Directory is, and why should I care about it and never heard about ACL abuse and all. Although I had attended a BPAD (Breaking and Pwning Active Directory) training which was provided by Nullcon but I was not confident enough to go for this course exam, since my day-today activity involves VAPT stuffs related to Web/Network/Mobile and sometimes basic malware analysis (very basic one :p).  I started doing offshore lab and took help from some friends in understanding few Active Directory concepts. I did many silly mistakes during the lab and learned a lot. Meanwhile I registered for Active Directory Lab Course and got it in a discounted offer for first 50 students of about 11k INR  ( 1 mont lab access) :). Before wasting time any further let's dive into the review. The course - Certification - Certified Red Team Professional The Course Content  - After paying the course fee,

Backdoring PE files using code caves : OSCE/CTP Module 0x03 (OSCE Preparation)

Hello Readers, This post will cover Backdooring of P.E file by using code caves . There are already good tools to do this for you eg. Backdoor Factory and Shelter which will do the same job and even bypass some static analysis of few antiviruses . I will be covering the manual approach of backdooring a PE file . Let's understand some terms : [x] PE file : The Portable Executable (PE) format is a file format for executables, object code, and DLLs, used in 32-bit and 64-bit versions of Windows operating systems. [x] Code Cave : Wikipedia says - "A code cave is a series of null bytes in a process's memory. The code cave inside a process's memory is often a reference to a section of the code’s script functions that have capacity for the injection of custom instructions. For example, if a script’s memory allows for 5 bytes and only 3 bytes are used, then the remaining 2 bytes can be used to add external code to the script." [x] Shellcode : Wikipedia - &qu

Hacking Thick Clients – Authorization Bypass

Hello Readers, This post will be focused on setting up a vulnerable thick client application and finding vulnerabilities. The blog post is an unofficial part of the on going series of post by NetSPI. NetSPI has released a vulnerable thick client app called BetaFast which has two versions - BetaBank and BetaFast based on 2-tier and 3-tier architecture respectively. The app is coded by Austin Altmann  and he is writing the walk-through series. Note: At the time of writing this blog, the walk-through/write-up for authorization bypass vulnerability was yet to be published by NetSPI and therefore I decided to create this blog post. All the credit for developing and maintaining this app goes to Austin and NetSPI team. You can find some of the cool write-ups here . Let's start. Setting up Betafast - 1. Download the files from github -  . 2. Extract and open the .sln file with