Client-side security for ecommerce

Know every script on your store. Catch the one that shouldn't be there.

StorefrontShield watches every script running on your storefront and flags any change the moment it happens — so a skimmer slipped into your checkout is caught in minutes, not after the chargebacks.

Get a free script scan See how it works

Continuous monitoring & evidence — built to meet PCI DSS 6.4.3 & 11.6.1

SCRIPT MONITOR · store.example.com ● LIVE

googletagmanager.coma7f3·c1VERIFIED

connect.facebook.net2c91·8dVERIFIED

scripts.clarity.ms8be0·4fVERIFIED

cdn.shopify.comf10a·77VERIFIED

checkout/assets/custom.js4d9c·2bVERIFIED

Script changed on checkout page — flagged in 4 min. Alert sent.

The threat

A skimmer doesn't break in. It hides in a script you already trust.

The FBI estimates e-skimming costs over $1 billion a year
— and most stores never see it happen.

It's invisible

Attackers add a few lines to a third-party script — a pixel, a widget, a tag — and copy card details as customers type them. No downtime, no error, no trace.

You can't watch what you can't see

A typical store runs 10–40 third-party scripts and can't account for half of them. Each one is an entry point you're not monitoring.

The rules changed

Since March 2025, PCI DSS v4.0.1 requires your entire storefront — not just the payment page — to be protected against script-based attacks.

How it works

Three steps. Running quietly in the background.

We set a baseline, watch it for change, and hand you the proof. You don't install anything.

STEP 01

Inventory

We load your store in a real browser and catalog every script that runs — who owns it, what it does, and a fingerprint of exactly how it looks today.

→ 111 scripts found · 4 need your sign-off

STEP 02

Watch

We re-check on a schedule and compare against that baseline. The instant a script is added, removed, or altered, you get an alert — with the diff.

→ hash 4d9c·2b ≠ baseline · ALERT

STEP 03

Prove

Each quarter you get a plain-English evidence pack — inventory, justifications, and change history — ready to drop straight into your self-assessment.

→ Q3 evidence pack · ready to submit

What a scan turns up

You're responsible for more scripts than you think.

A representative storefront scan. Platform code is largely your provider's job — but the marketing and analytics scripts you added are yours to monitor.

YOUR SCRIPTS — NEEDS MONITORINGLOADS

tag-managerGoogle Tag Manager7

marketingMeta (Facebook) Pixel2

analyticsMicrosoft Clarity2

marketingGoogle Ads / DoubleClick2

themeYour custom theme code3

✓ Every script grouped by who's responsible — you, your platform, or your theme.
✓ A written justification for each one, ready for your records.
✓ A flag on anything that loads from somewhere it shouldn't.
✓ A baseline fingerprint, so the next change is impossible to miss.

Built for PCI DSS v4.0.1

Exactly the controls the standard now asks for.

Two requirements became mandatory in March 2025. They describe what StorefrontShield does — so the evidence writes itself.

6.4.3

Manage payment-page scripts

Inventory every script, confirm it's authorized, and justify why it's there.

11.6.1

Detect tampering

Monitor for unauthorized change to scripts and the page, and alert on it.

SAQ A

Whole-site scope

The simplest self-assessment now requires your entire site to be protected against script attacks.

Straight about what we are

We're your monitoring partner — not a box-ticker.

StorefrontShield gives you the visibility, the alerts, and the evidence. We are not a Qualified Security Assessor and we don't sell you a certificate — we help you (and your assessor) get the work done, with no fear-selling and no compliance theater. You stay in control of your attestation.

See what's running on your store

Get a free script scan.

No install, no commitment. We'll send you a plain-English report of every script on your storefront and which ones need your attention.

Read-only · no install · typically back to you within 2 business days.