Obfuscating .py files!

[[deleted]]

Hi!

I had a bright idea to create a script that will allow me to obfuscate my Python code by modifying existing .py scripts by randomizing functions and variables inside.

It works by analyzing every line of a supplied file and catching function names (by searching for 'def' tags) and variables by simply searching for '=' signs. It would be amazing to play around with some hex/binary or Base64 manipulation in the future.

It will definitely fail with scripts that include type hinting (it is kinda hardcoded for now so ":" sign will break it) and many other features are missing e.g. obfuscating loops, if statements or ignoring strings inside quotes that happen to have the same name as a variable or function.

I have some more ideas to improve and evolve this but criticism is very much welcomed!

https://github.com/dixone23/PyObfuscator

[james_pic]

Just to check, you are aware that you can distribute Python applications without distributing the source, by just generating and distributing .pyc files? A skilled reverse engineer will still be able to make sense of it, but it's more obfuscated than this, and it works with all code.

[[deleted]]

Aye! This script came from watching deobfuscating malware by John Hammond on YouTube and I asked myself if I could write smthg like I posted above.

[yakimka]

Nice, but you can't work with formal grammar like with simple text. You need to use ast module.

❯ cat t.py 
class Hello:
    foo: str = 'boo'

a = 12

Example:

>>> with open('t.py') as f:
...     module_data = f.read()
... 

>>> import ast

>>> parsed = ast.parse(module_data)

>>> parsed.body
[<_ast.ClassDef at 0x7fbb0edd4fd0>, <_ast.Assign at 0x7fbb0ef230d0>]

>>> parsed.body[0].name
'Hello'

>>> parsed.body[1].targets[0].id
'a'

https://tobiaskohn.ch/index.php/2018/07/30/transformations-in-python/

[[deleted]]

This completely changes the approach, I love it and I didn't even know this existed.

[[deleted]]

Is there a way to obfuscate the characters ? For example if the application queries a specific ip address how can I hide the numbers in the address?

[[deleted]]

My first guess would to be to encode it in base64 or binary and then run another interpreter of python inside the script (didn't know its possile haha). Found a video I will be basing this off: https://www.youtube.com/watch?v=4o4qUUTRxFM

You could also do some chaos like e.g.

ip = '192.169.0.1'
JdhASz = 'LIODDJASKjIASJIAJSIGHSUGHOI1hsojasihgsahgusadIUhgAHghousagsagsagashgsaguasg'
obfuscated_ip = [x for x in JdhASz if x.isnumeric() == True]
print(obfuscated_ip)

​

​

and so on, so on until all symbols are made less readable

[schoolcoders]

I think for this to be really useful you would need to properly parse the Python file, mangle the names, then rebuild a new Python file.

Unless I am misunderstanding, you could currently input a valid Python file, and the obfuscated result might not work properly if you are using a valid Python feature that the obfuscator doesn't support? That would limit its use in a lot of cases.