PDF download Download Article PDF download Download Article

JavaScript injection is a process by which we can insert and use our own JavaScript code in a page, either by entering the code into the address bar, or by finding an XSS vulnerability in a website. Note that the changes can only be seen by you and are not permanent. This is because JavaScript is a "client-side" language.

Method 1
Method 1 of 1:

Using JavaScript Injections

PDF download Download Article
  1. Try these injections:
    • Note - If you use Firefox, you will have to use another way, like cmd-shift-k on a Mac
    • javascript:alert("Hello!");
    • To bring up an alert box saying "Hello!":
    • To bring up 2 alert boxes, the one in the front will say "Hello" and once you click OK, the one saying "World" will appear:
    Advertisement
    • To change the value of form [0] to something:
    • To change the background color to blue. You can put any other color in the place of blue to change it to a different color:
  2. \t\t" + location.protocol + "//" + location.hostname + "/" + "\nThe address URL is:\t\t" + location.href + "\n" + "\nIf the server names do not match, this may be a spoof.");
    • To see the real server name of the site you are looking at. You should use it if you think that you are viewing a spoofed website, or anytime just to make sure:
  3. javascript:R=0; x1=.1; y1=.05; x2=.25; y2=.24; x3=1.6; y3=.24; x4=300; y4=200; x5=300; y5=200; DI=document.images; DIL=DI.length; function A(){for(i=0; i-DIL; i++){DIS=DI[ i ].style; DIS.position='absolute'; DIS.left=Math.sin(R*x1+i*x2+x3)*x4+x5; DIS.top=Math.cos(R*y1+i*y2+y3)*y4+y5}R++}setInterval('A()',5); void(0);
    • To make pictures fly around. Make sure to find a site like Google Images so there are more pictures!(If you press the refresh button, it goes really fast, but might only work with macOS):
  4. javascript:R=0; x1=.1; y1=.05; x2=.25; y2=.24; x3=1.6; y3=.24; x4=300; y4=200; x5=300; y5=200; DI=document.images; DIL=DI.length; function A(){for(i=0; i-DIL; i++){DIS=DI[ i ].style; DIS.position='absolute'; DIS.left=Math.cos(R*x1+i*x1+x2)*x4+x5; DIS.top=Math.cos(R*y1+i*y2+y3)*y4+y5}R++}setInterval('A()',5); void(0);
    • To spin circle of pictures. It funnels the pictures in a snake-like motion:
    • To move things around on the webpage:
  5. Advertisement

Community Q&A

Search
Add New Question
  • Question
    Is this the equivalent of the JavaScript console?
    Community Answer
    Yes; this is much less limited, though. The JavaScript console in the dev tools has features such as auto-completion and can show your history of executed commands. Additionally, you can check things such as break points for analyzing and debugging your code.
  • Question
    In Step 3, how do I select a form? The example specifies forms[0], but how do I actually specify a certain form if the code has several forms within it?
    Community Answer
    You can select forms from the website using document.forms. The forms[0] indicates that it is the 1st form on the page, because the collection starts at 0. You can make a form with the HTML form tag, and you can learn more at sites like w3schools.
Ask a Question
      Advertisement

      Video

      Tips

      • Only you can see the changes.
      • The changes are not permanent. It's a static change that won't affect any server information.
      • If you're using a browser with an address bar that doubles as a search bar (e.g., Google Chrome), make sure that after you type in the JavaScript code, you select your address bar for processing the code, not the search function.

      Show More Tips
      Submit a Tip
      All tip submissions are carefully reviewed before being published
      Name
      Please provide your name and last initial
      Thanks for submitting a tip for review!
      Advertisement

      Expert Interview

      Thanks for reading our article! If you’d like to learn more about dealing with html, check out our in-depth interview with Jessica Andzouana .

      About This Article

      Thanks to all authors for creating a page that has been read 521,551 times.

      Is this article up to date?

      Advertisement