MB-R090
Payment page tamper monitoring includes payment-page scope, alerting, and CSP reporting or scheduled integrity detection.
Payment-page tampering can happen through compromised extensions, tag managers, deployment artifacts, or injected JavaScript. If no one is watching for checkout changes, skimming code may remain active for a long time.
Tamper monitoring creates signals when checkout scripts, DOM behavior, CSP reports, or deployed files change unexpectedly.
Checkout scripts can change through tag manager without approval, alerting, or review.
# Tamper monitoring missing → FAIL
CSP reports, tag manager approvals, and file integrity checks alert on unexpected checkout script changes.
# Monitoring ready → PASS