Examine source code of Ecosia Ad

{
  "manifest_version": 2,
  "name": "Ecosia Ad",
  "version": "1.0",
  "description": "Adds a yellow background to all ecosia ads",
  "icons": {
    "48": "icons/ecosia-ad48.png"
  },
  "content_scripts": [
    {
      "matches": [
        "*://*.ecosia.org/*"
      ],
      "js": [
        "ecosiaad.js"
      ]
    }
  ]
}