Inside the Fight Against Card Testing: How a Payments Platform Beat Fraudsters at Their Own Game

Fraudsters thrive on weak points, and for a long time, a payments platform unknowingly provided the perfect playground for card testers. With no validation or verification checks, it was easy for attackers to test stolen card credentials, knowing exactly when and why their attempts failed. The result? A flood of fraudulent low-value transactions, thousands per day, that drained resources and threatened the integrity of their platform.

The Problem: A Fraudster’s Playground

This payments platform wasn’t dealing with traditional fraud. They don’t sell tangible goods, so chargeback concerns weren’t the main issue—at least not yet. Their biggest vulnerability was being exploited by bad actors looking to test cards in bulk, often placing lower-dollar transactions across different time zones, refining their techniques every time a transaction failed.

Fraudsters were working full-time to attack the platform, and in response, the payments platform’s team was forced to dedicate nearly all their energy to fighting them off. It was a battle they were losing.

The Turning Point: A Smarter Approach to Defense

That’s when we stepped in. At Spec, we don’t just block fraud—we study its patterns, adapting protections in real-time as fraudsters attempt to evolve their tactics. Our first step with this payments platform was gaining a deep understanding of the behaviors driving the attacks.

With our extensive data insights and the flexibility of our platform, we built highly detailed workflows to detect fraudulent activity while ensuring legitimate users weren’t impacted. Rather than relying solely on static rules, we developed dynamic protections that adjust as fraudsters change their approach.

One of our most effective tools is the use of honeypots—strategic traps designed to lure fraudsters into revealing their tactics without alerting them that their attempts have already been neutralized. Unlike traditional blocking mechanisms that notify fraudsters of failure, honeypots keep them engaged in behaviors that are continuously prevented, allowing us to gather more intelligence on their evolving methods.

This deception works to our advantage. Fraudsters believe they are making progress, but in reality, they are exposing their strategies while failing to bypass our defenses. By capturing their behavioral patterns, we refine our protections in real-time, staying ahead of emerging threats and making it increasingly difficult for attackers to succeed.

Results: From Thousands of Attacks to Nearly Zero

The impact was immediate. In a matter of days, this payments platform went from thousands of daily fraudulent attempts to just a handful—if any. A few persistent fraud groups kept trying, but they were getting nowhere.

One of our biggest challenges was avoiding false positives, especially on Sundays when legitimate transaction activity surged. We noticed that fraudsters ramped up attacks on Thursdays and slowed down by Sunday night. To counter this, we adjusted our rules dynamically to account for the different genuine activity observed specifically on Sundays.

The Bigger Picture: Fraud Teams Need to Prioritize What Matters

The payments platform’s CEO, who had firsthand experience with card testing challenges, was thrilled with the results. Before working with us, their fraud team spent nearly all their time fighting off attacks. Now, with the problem under control, they were free to focus on innovation and supporting their real customers.

This case highlights an important lesson for fraud, product, and customer service teams everywhere: Instead of trying to tackle every fraud use case at once, start with the biggest threat. Solve for that first, and build from there.

Too many fraud teams rely on a patchwork of legacy tools simply because that’s what they’ve always used. While Spec integrates well with other vendors, we don’t believe in unnecessary complexity. If we can solve the problem effectively, there’s no need to layer on redundant solutions.

What’s Next: Beyond Card Testing

Now that this payments platform has a grip on card testing, we’re exploring the next frontier—chargeback prevention from additional fraud-types. Instead of outright blocking transactions, we’re identifying patterns in chargeback reasons to preemptively reduce risk. With our dynamic approach, the payments platform can stay ahead of fraud while ensuring that their real users always have a seamless experience.

Fraud is constantly evolving, but so are we. And for this payments platform, the battle isn’t just about stopping attacks—it’s about taking back control.

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