SLAE64 Exam - Assignment 7 of 7 (Cryptor)

This post is the seventh of 7 exam assignments of the Pentester Academy's x86/64 Assembly and Shellcoding on Linux.

SLAE64 - 1501

Success in these 7 assignments results in the Pentester Academy's SLAE64 certification.

http://www.securitytube-training.com/online-courses/x8664-assembly-and-shellcoding-on-linux/index.html

All 3 files  used in this assignment are here:
https://github.com/clubjk/SLAE64-3/tree/master/exam/cryptorAssignment:

• Create a custom crypter like the one shown in the “crypters” video

• Free to use any exisSng encrypSon schema 

• Can use any programming language 

I chose an AES encryption script created by Blu3Gl0w13. Check out his excellent blog here.

I elected to use the execve-stack shellcode as a base for this assignment.  I extracted its shellcode using a modified objdump command.



I pasted the shellcode into encryptor.py as well as choosing a key of 'clubjk'.




I executed the script and it outputted encrypted shellcode.



I pasted this encrypted shellcode in decryptor.py as well as adding the key of 'clubjk'.



I executed the encryptor.py and the decrypted execve-stack shellcode executed uneventfully.



It worked. Yay.

Files used in this assignment:

execve-stack.nasm
encryptor.py
decryptor.py

All are here:
https://github.com/clubjk/SLAE64-3/tree/master/exam/cryptor