JSut Duck it Up

Writeup by hgarrereyn

  • Reverse Engineering
  • 75 points
  • Description: What in the world could this be?!?! file


At first glance, this file looks a little crazy. It only contains the following characters: []()+!. However, this problem is actually quite easy to solve. What we are looking at here is javascript type coercion taken to the max.

When you try to add two javascript objects of different types, the runtime engine will try to modify types in order to produce any result.

All we have to do to solve this problem is copy the file and paste it into the console of a browser where it will be converted into the following function (and immediately executed):

(function() {

Flag: aw_yiss_ducking_breadcrumbs_964eae3b


  • JSFuck provides a utility to create the same kind of obfuscated javascript as above.

results matching ""

    No results matching ""