Bluffy is a utility which was used in experiments to bypass Anti-Virus products (statically) by formatting shellcode into realistic looking data formats.
So far, we implemented:
$ python3 bluffy.py -h ⣇⣿⠘⣿⣿⣿⡿⡿⣟⣟⢟⢟⢝⠵⡝⣿⡿⢂⣼⣿⣷⣌⠩⡫⡻⣝⠹⢿⣿⣷ ⡆⣿⣆⠱⣝⡵⣝⢅⠙⣿⢕⢕⢕⢕⢝⣥⢒⠅⣿⣿⣿⡿⣳⣌⠪⡪⣡⢑⢝⣇ ⡆⣿⣿⣦⠹⣳⣳⣕⢅⠈⢗⢕⢕⢕⢕⢕⢈⢆⠟⠋⠉⠁⠉⠉⠁⠈⠼⢐⢕⢽ ⡗⢰⣶⣶⣦⣝⢝⢕⢕⠅⡆⢕⢕⢕⢕⢕⣴⠏⣠& #10358;⠛⡉⡉⡛⢶⣦⡀⠐⣕⢕ ⡝⡄⢻⢟⣿⣿⣷⣕⣕⣅⣿⣔⣕⣵⣵⣿⣿⢠⣿⢠⣮⡈⣌⠨⠅⠹⣷⡀⢱⢕ ⡝⡵⠟⠈⢀⣀⣀⡀⠉⢿⣿⣿⣿⣿⣿⣿⣿⣼⣿⢈⡋⠴⢿⡟⣡⡇⣿⡇⡀⢕ ⡝⠁⣠⣾⠟⡉⡉⡉⠻⣦⣻⣿⣿⣿⣿⣿⣿⣿⣿⣧⠸⣿⣦⣥⣿⡇⡿⣰⢗⢄ ⠁⢰⣿⡏⣴⣌⠈⣌⠡⠈⢻⣿⣿⣿⣿⣿⣿⣿⣿⣿&# 10495;⣬⣉⣉⣁⣄⢖⢕⢕⢕ ⡀⢻⣿⡇⢙⠁⠴⢿⡟⣡⡆⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣷⣵⣵⣿ ⡻⣄⣻⣿⣌⠘⢿⣷⣥⣿⠇⣿⣿⣿⣿⣿⣿⠛⠻⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿ ⣷⢄⠻⣿⣟⠿⠦⠍⠉⣡⣾⣿⣿⣿⣿⣿⣿⢸⣿⣦⠙⣿⣿⣿⣿⣿⣿⣿⣿⠟ ⡕⡑⣑⣈⣻⢗⢟⢞⢝⣻⣿⣿⣿⣿⣿⣿⣿⠸⣿⠿⠃ 0495;⣿⣿⣿⣿⣿⡿⠁⣠ ⡝⡵⡈⢟⢕⢕⢕⢕⣵⣿⣿⣿⣿⣿⣿⣿⣿⣿⣶⣶⣿⣿⣿⣿⣿⠿⠋⣀⣈⠙ ⡝⡵⡕⡀⠑⠳⠿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⣿⠿⠛⢉⡠⡲⡫⡪⡪⡣Convert shellcode into ✨ different ✨ formats!Written by: ~ Mez0 ~ Michael Ranaldousage: Bluffy [-h] -b -o -moptional arguments: -h, --help show this help message and exit -b , --bin Specify bin file to load -m , --mask Specify the mask for the shellcode -x , --xor XOR the payload -p , --preview Preview the created format -pp, --payload_preview Preview the payload prior to C formatting --list List all the available masks
Requirements and installation
The following items must be installed prior to using Bluff:
python3.9 or greater:
sudo apt install python3.9
sudo pip3 install rich
Depending on whether its going to be ran on Kali, Ubuntu 18, 19, 20, and so on, the process of getting and building with
pcre2.8 may be different.
For us on Ubuntu, it was developed on:
$ lsb_release -aNo LSB modules are available.Distributor ID: UbuntuDescription: Ubuntu 21.04Release: 21.04Codename: hirsute
In order to link
.a file had to be included within:
The simplest way to thus acquire and install is to run the following commands (after double checking your architecture etc.):
sudo apt install mingw-64sudo wget https://packages.msys2.org/package/mingw-w64-x86_64-pcre2?repo=mingw64 -P /usr/lib/gcc/x86_64-w64-mingw32/10-win32
To build a payload, get your binary file. For this example, we used calc.bin, which just loads calc.exe as a proof of concept. As Bluffy only seeks to evade static analysis using steganography, by hiding the binary within an otherwise innocuous file, you will need to do further research to ensure that your payload also evades dynamic detection.
bluffy, choosing a mask of your choice and providing your .bin file:
python ./bluffy.py -b calc.bin -m css -x
Check your payload, then build it. To build your payload, copy the .h file bluffy creates, rename it css.c, run make to build it to an executable, then test using the included examples directory:
mv css.h examples/css/css.hcd examples/cssmake
This will use the included "main.c" to build an Windows executable. Test this to confirm. If you have also used calc.bin, you should be greeted by a new Calc window opening. If so, congratulations!
For more details on using Bluffy and a walkthrough of how it works and what the output looks like, check out our blog
Here is a full example: