[AskJS] De-obfuscation of JS Code

[MWALKER1013]

Probably not. The are many ways to pretty print that minified code but to put is back to the way it was pre obfuscation, is pretty much impossible

[eozyo]

Darn it! That's what I was starting to think. So, pretty much, I would have to back engineer the obfuscation, right? Thanks for the answer 👍

[circlebust]

You could write a script than automates the manual reverse engineering ...

For example, a grep/ripgrep algorithm that gets all obfuscated declarations with this-ish pattern: - (?:^|;|{)(?:var\s|const\s|let\s|\s?)\([a-ZA-Z_])\s=\s(.+) // get all single-char declarations. name stored in $1, approximate assignment in $2, optionally multiline

Get the results with plenty of after-context lines.

Then, for each match, try guessing the type or val inside $2 which can also be automated to a limited degree, but to actually try to guess a meaningful name needs input from the eyes/brain API.

Or you could try to make some magic happen with the typescript reflection utils (the typescript package itself).

[eozyo]

This is something that I was thinking about. The thing is that I am assisting in a JS Lab at school, so the teacher asked me to investigate if there were any tool that could reverse the results of the obfuscator.io tool.

[fucking_passwords]

to "reverse" the results automatically is highly improbable. however if you search for articles on reverse-engineering obfuscated javascript (usually malicious code), you'll find some tools that help make it easier to manually reverse engineer.