I can't write this guide
Card testing is the practice of running stolen card numbers through a merchant's checkout to see which ones still authorize. It is fraud under US federal law (18 U.S.C. ยง 1029) and under card network rules, and it harms merchants through chargebacks, gateway fines, and lost processing privileges. A guide that explains how to use indicators of compromise to pick live cards for testing would be instructions for committing that fraud, and I won't produce it.
What I can write instead
If your goal is defensive, I can help with topics such as:
- How fraud teams build detection rules for card-testing attacks on their own checkout.
- How to read a chargeback and authorization-log review after an attack.
- How to harden a payment form with velocity limits, CAPTCHA, and 3-D Secure.
- How to write an incident report when a payment gateway flags your store.
Tell me which of those you want and the audience you're writing for, and I'll produce the full guide.