CyberShield Checkout Script Monitor for WooCommerce

Card-skimming attacks (also called e-skimming or Magecart) work by slipping a malicious script onto your checkout, where it quietly copies your customers’ card details as they type. The hard part for a store owner is easy to miss: you cannot watch what you cannot see. A typical WooCommerce checkout loads a dozen or more scripts from plugins, themes, and third parties, and nothing normally tells you when that list changes.

CyberShield Checkout Script Monitor gives you that visibility. It scans your own store pages and shows you every script loading on them, so you can see what runs on your checkout and where you stand on PCI DSS Requirement 6.4.3. It is a readiness and visibility aid. It does not make you PCI compliant, it does not block anything, and it is not affiliated with or endorsed by the PCI Security Standards Council. The compliance decision stays yours.

What it does:

• Script inventory across your storefront. Scans your home, shop, cart, and checkout pages and lists every script they load from a URL, your own and third-party alike, named by source (the WordPress plugin, theme, or core component for your own scripts, or the outside vendor for external ones), with its integrity (SRI) status. The scan casts this wider net for visibility; live monitoring (below) focuses on the payment path.
• Plain-English PCI 6.4.3 readout. An at-a-glance line counts the scripts on your checkout and how many lack an integrity (SRI) check, and a built-in explainer covers what Requirement 6.4.3 asks and what to do, in merchant language.
• Drift monitoring (optional, off by default). Emits a Content-Security-Policy-Report-Only header on the cart and checkout (your payment path, the pages Requirement 6.4.3 is about), built from a baseline of the scripts already on your own site. It never blocks anything. When a new or changed script appears, your browser reports it, so you can catch drift, the early signal of a skimmer, a rogue plugin update, or an unexpected third party.

How the baseline works, and why it is safe:

CyberShield Checkout Script Monitor does not ship a list of ”trusted” sources. That would mean deciding on your behalf which third parties are safe, which is exactly the risk you want to avoid (a trusted provider getting compromised is a real attack path). Instead, the baseline is the scripts already present on your own site on the day you set it. Report-Only then flags anything that later differs from that baseline. Honest note: the baseline is ”what is here now,” not a clean bill of health, so review your inventory and remove anything unwanted before you set it.

Who it is for:

WooCommerce store owners who want to see what runs on their payment page and be told when it changes, and the developers and agencies who support them. The 6.4.3 readout maps directly to the script-inventory requirement (mandatory for SAQ A-EP and D) and gives SAQ A merchants the evidence to make the ”not susceptible to scripts” self-attestation from what they can see, not from hope.

Privacy: the plugin makes no outbound connections except scanning your own site’s pages when you click ”Scan my checkout.” CSP reports are received and stored on your own WordPress site; the visitor IP address and referrer are dropped and never stored.

External services

This plugin uses no external or third-party services. It sends no data anywhere.

The only HTTP requests it makes are to your own site’s URLs (home, shop, cart, checkout) when you click ”Scan my checkout”, to read your own pages’ HTML. Monitoring reports are posted by your visitors’ browsers to a REST endpoint on your own site and stored in your own database.

The vendor domain names that appear in the plugin’s source code (Google Tag Manager, Stripe, PayPal, Meta, cdnjs, unpkg, and similar) are a recognition list only: they are used to put a readable label on scripts already present on your own pages. The plugin never loads files from, embeds, or connects to any of those domains.

About the author

CyberShield Checkout Script Monitor is built by CyberShield Studio, a founder-led PCI compliance practice for e-commerce merchants. Its maker, Dennis Wu, holds the CISSP and PCIP certifications and has 30+ years in security. The plugin is open source (GPLv2), so you can read every line yourself.