how to deobfuscate javascript [closed]

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can any one tell me how to de-obfuscate this?

É=-~-~[],ó=-~É,Ë=É<<É,þ=Ë+~[];Ì=(ó-ó)[Û=(''+{})[É+ó]+(''+{})[ó-É]+([].ó+'')[ó-É]+(!!''+'')[ó]+({}+'')[ó+ó]+(!''+'')[ó-É]+(!''+'')[É]+(''+{})[É+ó]+({}+'')[ó+ó]+(''+{})[ó-É]+(!''+'')[ó-É]][Û];Ì(Ì((!''+'')[ó-É]+(!''+'')[ó]+(!''+'')[ó-ó]+(!''+'')[É]+((!''+''))[ó-É]+([].$+'')[ó-É]+'\''+''+'\\'+(... Masked for confidentiality reasons

Answer 1

Look for the "()" in the end. Those are for executing the obscured function code. If you remove the last one and use "toString()" instead in node you will get the following (After formatting a bit):

function anonymous() {
   na = prompt('Entrez le mot de passe');
   if(a == 'I changed this to not make it too easy for you' {
      alert('bravo');
   } else {
      alert('fail...');
   }
}

Try it yourself, but always be careful, since if you are not careful this kind of code can run harmful stuff on your computer.

PS: A few more words about how it actually works. Those weird french seeming letters everywhere are just variables, which are defined in the beginning. É for example has the value of 2, since using the bitwise not operator on an empty array results a -1, and -~-(-1) = 2. All those backslashes are then used in combination with this numeric variables to get characters which eventually form the code of the function.