24 votes

How to deobfuscate an obfuscated javascript file like this?

There are a few tools that you might try when wanting to analyze JavaScript: JSDetox Malzilla JavaScript Deobfuscator ExtractScript JS-Beautifier JS-Unpack (see also blog) Rhino Debugger Firebug ...
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  • 18.1k
11 votes
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How do I reverse this javascript code? How is it packed?

1. The script writes a <script src=...> tag at the end, so to know what it is doing, you could change the last document.write to a console.log or other defanging measures to see that this is ...
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  • 446
9 votes
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How to deobfuscated javascript?

UPDATE Based on @ws's comment and @nderscore's code, use this JSFiddle to decode the thing. To find the password that this script asks for, you can use a simple debugging trick. Go to JSFuck and ...
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  • 1,253
8 votes
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How work this obfuscation, and how deobfuscate?

This obfuscated code is taking advantage of the wide possibilities to name Javascript variables. This makes a simple-obfuscated Javascript code to look much more scarier. As noted in the great ...
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  • 8,659
6 votes

What is a good tools to reverse the effects of Minify on JavaScript?

I recently tried http://www.jsnice.org/ on 50+KB of a single minified JavaScript file containing lots of dynamic modification code that Cordova's runtime refused to execute (for an app targeted at ...
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5 votes

How work this obfuscation, and how deobfuscate?

It just uses very difficult to read variable names and do some JS trickery to confuse you what it does. If you replace those strange characters you'll get a bit of more readable form a=~[]; a={___:++...
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5 votes
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Obfuscated code analysis - can unused variables be ignored?

This might be true that those variables are added only to confuse analysis but remember that in Javascript there are so many ways to access the variable that I would take such info from an automated ...
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5 votes
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How can I deobfuscate this javascript code

The special "accent" letters are just a distraction. You can use a text-editor to replace them with "standard" letters and the code would still work. Let's add a newline after each semicolon: É=-~-~[...
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  • 479
5 votes
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How can I modify or decompile Hermes JS bytecode?

My friend made this tool: hbctool, a Hermes bytecode disassembler/assembler. This will help you disassemble the file into a more readable format (similar to hbcdump), so you can modify and re-assemble ...
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  • 66
4 votes

Analyzing highly obfuscated JavaScript

In addition to the other useful links here, I recommend to try Malware-Jail Sandbox for semi-automatic Javascript malware analysis, deobfuscation and payload extraction. Written for Node.js malware-...
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  • 183
4 votes
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reverse javascript crackme encryption method algorithm

To extend on EWD-0- about the reversibility of RC4 here's how I tried it: From your actual code and reversing it a little to get "input128" encoded: arr = [99, 116, 115, 37, 16, 120, 211, 90, 197, ...
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  • 156
4 votes

How to get Video URL from embedded Link in Twitter

youtube-dl is a nice program to download media content from a lot of websites, including twitter (and despites program name). It is open source, studying it can help understand how to retrieve the ...
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4 votes

How to copy video address from tweet?

I could not quite track how exactly it's done but youtube-dl can do it. Run it with -v or -g to see the final video URL: C:\Work>C:\Python27\Scripts\youtube-dl.exe -v https://twitter.com/starwars/...
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  • 34.9k
3 votes

How to get Video URL from embedded Link in Twitter

You were looking at the wrong piece of code. Twitter features lightly obfuscated javscript. Bring it to order and you'll receive something like this: { "duration": 55322, "scribe_widget_origin": true,...
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  • 2,826
3 votes

Reverse engineering a java applet using python/Javascript

If I understand well, you would like to reverse a Java applet in order to plug your own tool on a specific API (which is incidentally a trading platform). I do not know why you are speaking about ...
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  • 18.1k
3 votes
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Deobfuscating a javascript file

Well, so, you can use http://jsbeautifier.org/ with unescape printable chars to get the top var decoded, then, if you look closely, you should see that the values of the var are used everywhere with ...
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  • 586
3 votes
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How decrypt hexadecimal javascript code?

Those hex values could represent anything. Look for online converters that convert hexadecimal to text (consider various formats), dec, etc. and see if the results make any sense. If not, then they ...
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  • 2,154
3 votes
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Is deobfuscation of my javascript code hard or easy?

Resolved. generally nothing in js is impossible to reverse in this case the 'alert' string in plain text give me a big help, because I simply started to resolve function value one step back at time. ...
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  • 183
3 votes
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Is it possible to completely reverse this code?

Having such code the first thing to do is to analyze what part is the obfuscation algorithm and what's the actual code. Here' it's not that difficult as all the code is on top. So let's analyze it ...
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2 votes

Try to deobfuscate multi layered javascript

You could try using de4js. For the javascript snippet in the original post, de4js produces the following output: var _0x2815 = ["3 1(){2 0=5;4 0}", "|", "split", "x|myFunction|var|function|return|", "...
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2 votes
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LastPass Android javascript behaviour

In short, no. If they're going to implement the "crypto" in Javascript in this way there isn't anything you can do beyond more obfuscation. This is 100% applicable to this situation but see MataSano's ...
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  • 972
2 votes

What kind of JS obfuscation is this?

This is dean edwards' js packer : http://dean.edwards.name/packer/. I see it quite frequently being used to obfuscate scripts as it is freely available. It's written in Javascript but there are also ...
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  • 2,168
2 votes
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What kind of JS obfuscation is this?

you can either print out the eval values on a custom html page using something like <html> <body> <script> document.write('<textarea cols="120" rows="10">'); document.write(...
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  • 586
2 votes

Frida manipulating arguments - Android

If I understand your question correctly, you want to change the parameter, v, inside the inner function. Right? If that's the case, you would already have access to the v argument inside your inner ...
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  • 121
2 votes
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IDA Pro Alternative for JavaScript?

Have a look at https://github.com/scottrogowski/code2flow for generating callgraphs. Turn your Python and Javascript source code into DOT flowcharts Code2flow will sweep through your project ...
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  • 7,342
2 votes

How to call an item of a Javascript array?

The variable _0xe984 in your example is an array of strings, therefore, calling it with _0xe984("0xa") is actually to call as if it was a function that gets the string "0xa" as a parameter. Thus, the ...
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  • 8,659
2 votes

would be possible to deobfuscate javascript code?

All the strings you see \x41\x42\x43 are nothing but normal chars encoded as hex of their ascii values. You can decode them as follows: >>> "\x41\x42\x43".decode("utf-8") u'ABC' by trying ...
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2 votes

How do I decode this JavaScript code?

You can use this tool to partial deobfuscate that code: http://jsnice.org/ In that case I get this: 'use strict'; (function(data, i) { /** * @param {number} isLE * @return {undefined} */ ...
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2 votes
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Is v8's --print-bytecode safe?

--print-bytecode is not safe. echo "process.exit(42)" > test.js node --print-bytecode ./test.js It exists with status_code = 42. So that code is getting executed. It is not safe.
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  • 1,664
2 votes
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Load a *.dylib or *.so object into the Javascript V8 runtime?

I was misinterpreting the context of the comment in the original link, it seems. I was under the impression that Module.load was a v8-ism, while it in fact appears to be a Frida-API. https://frida.re/...
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