How to decode this javascript?

Question

My question is how can I decode this JavaScript and how is encoded (with which program or online tool).

Here is the JavaScript that I want to decode: http://pastebin

Answer 1

Have a look at: http://www.labnol.org/software/deobfuscate-javascript/19815/

They show you how can you do something like that, it's basically a matter of using chrome debugger to "beautify" the code and make it easier to read.

Some versions of chrome don't have the command on a context menu, just look for the command "Pretty print" (has a icon like -> {})

Once done that, you can use a javascript console to evaluate small snippets of code to reverse engineer it. Eg. the expression (at the beginning of your code)

1) (s\u0065lf + ([] * 0) * 1)
2) '\x5B'
3) ((s\u0065lf + ([] * 0) * 1)[0 ^ 0] == '\x5B')

returns this string on my browser

1) "[object Window]0"
2) "["
3) true

Just find the starting point and follow from there. Obfuscated code follows the same rules as normal one, it's just all messed up.