How can I decode this encoded JavaScript file?

Question

I have to deal with a very strange JavaScript file. It's called with a standard

<script src=XXXX.js type=text/javascript></script>

but XXXX.js is somehow packed/encrypted/whatever. The first characters are:

#@~^3wcAAA==@#@&0; mDkW

and there is not any pattern in it. there isn't any sign of known function as eval or equivalent.

How can I manage to read it's content? Is it a character set trick?

Answer 1

The creator might have used some kind of javascript obfuscator tool.

Try using the deobfuscator tool-plugin for firefox:

https://addons.mozilla.org/en-us/firefox/addon/javascript-deobfuscator/

Answer 2

You should look for the first few characters of your string, which could lead you to the right tool. I don't want to spoil the fun here, so I leave the rest to you ;)

If you know the method, I can recommend Cyber Chef to decode your script