Funds will mostly be used for my boba milk tea addiction. You may also send me some tips if you like my work and want to see more of such content. I hope these tabs have been helpful to you. Therefore, the same concept applies that we need to hunt for the flag somewhere in the memory which we know the start of the flag is “HTB This remaining shellcode is usually placed somewhere else in the memory not choose by the memory. As such, Egg Hunter is a shellcode that will locate the remaining shellcode based on the TAG/EGG that will help to identify the start of the remaining shellcode. Crafting the Egg Hunter shellcodeĮgg Hunter is often used when there is not enough space to place a shellcode that requires lots of bytes. Since the flag is being relocated randomly and the program accepts our input as a shellcode, we can use the Egg Hunter’s technique. Get our input and calls it, treating our input as a shellcode The program we are seeing is a dummy flag while the program run on the server will have the real flag.įig 5d. If we look at the strings in the program (press key SHIFT+F12), we can see that the flag is stored in the program itself. Reverse engineering Checking strings in Hunting So it seems like our input will not affect it. The program being debugged has been started already.īoth shows that it crashes at address 0x5655a1a0. Program received signal SIGSEGV, Segmentation fault. Starting program: /home/soulx/Documents/CTF/HackTheBox/Pwn/Hunting/hunting If we try to launch Hunting in GDB, run the program, input some random values, it will show the same crashed address. If we do not input any content, the program will terminal in 3 seconds. The example below shows that I input string “abcd” and an error appears. If you input content, it will crash and shows a segmentation fault error. The 1 cybersecurity upskilling platform Hack The Box gives individuals, businesses and universities the tools they need to continuously improve their cybersecurity capabilities all in one place. The program is really simple where there is an empty prompt. I am not sure about Parrot, BlackArch, etc. IDA (You can use other reverse engineering tools as well)įor Nasm and LD, it should already be available if you are using a 32-bit or 64-bit Kali.You may also download the IDA database of what I have reverse engineered for Hunting where I have made changes to the names of variables, functions, and added comments here.Īlternatively, you can download the whole folder which contains exploits, the hunting file, the IDA database, the assembly file, etc, from this folder here. There is only 1 file provided which is a 32-bit ELF file: Hunting Pwn challenge on HackTheBox Files provided
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