What is the best definition of card testing fraud?

• A. Testing one or multiple cards on one site to see if the card is still valid before using it on another site to make payment.
• B. Using stolen cards to make payments so as to identify which credentials are still usable
• C. Disputing a payment the rightful cardholder made willingly
• D. Impersonating a business and accepts payments without delivering a good or service

Answer: (A)

Card testing fraud is the act of checking whether a payment card is live and usable by processing small transactions on one site to see if the card still works before using it on other sites. This approach lets a fraudster quickly separate valid, usable cards from expired or blocked ones, focusing larger fraudulent activity only on cards that pass the test. The best definition matches this precisely: testing one or more cards on one site to see if the card is still valid before using it on another site to make payment. In real scenarios, this might involve tiny charges or pre-authorizations that are less risky for the attacker while confirming card viability. The other scenarios describe different kinds of fraud (disputing legitimate charges, impersonating a business, or broader credential testing) that aren’t about validating a card’s usability on a single site before moving to others.