How Abstract kept a crypto trading platform online during a major DDoS attack
The attack
It started as a spike in sign-up attempts. Then it became a flood.
A fast-growing cryptocurrency trading platform found itself under a large-scale DDoS attack targeting its user registration flow. Bad actors were hammering the system with fake and disposable email addresses, thousands of requests designed to overwhelm infrastructure, disrupt service, and force their way in.
Usage spiked. The platform's systems were under serious strain. Without a way to screen and reject the fraudulent requests in real time, they would have gone down.
They didn't, because Abstract was already in place.
The setup
The platform had integrated Abstract's Email Reputation directly into their AWS Cognito sign-up flow well before the attack. Every registration attempt triggered a real-time validation check before an account could be created, screening for three key signals:
- Deliverability: Undeliverable emails are rejected outright
- Disposable status: Temporary or throwaway addresses are blocked immediately
- Domain age: Domains registered less than two years ago are rejected, cutting off newly spun-up fraudulent domains at the source
Simple, fast, and (as it turned out) exactly what was needed when the attack came.
Holding the line
When the DDoS hit, Abstract became the platform's most critical line of defense. The vast majority of malicious sign-up attempts were using fake or disposable emails, and every single one was caught and rejected before reaching the platform's core systems.
Legitimate users were unaffected. The attackers got nothing.
"When the attack hit, our usage spiked massively. Abstract kept screening every request without missing a beat. The thing is, without it we had no way of telling the difference between fake emails trying to take us down and real customers trying to use our service. Abstract gave us that visibility instantly. Without it, we would have gone down." — Head of Security, Crypto Trading Platform
Adapting as attacks evolved
As the initial wave was brought under control, the attackers adapted. They discovered that certain domains could intentionally slow down responses, exploiting a timeout threshold in the validation flow and slipping past checks under a fail-open policy.
The team responded with two additional layers built around Abstract's data:
- Response caching: Validation results for known domains are cached, accelerating repeated checks and cutting off slow-domain exploits
- Velocity checks: Any domain appearing more than five times in a single day is automatically flagged and rejected, neutralizing bulk sign-up abuse
The attacks subsided. Today, usage sits at a steady ~100 requests per day, a fraction of what the system proved it could handle under fire.
Results
Major DDoS attack repelled. Fake and disposable email volumes that would have taken the platform offline were screened and blocked in real time.
Zero disruption for legitimate users. The validation layer stopped bad actors without adding friction to genuine sign-ups.
Attack evolution countered. Caching and velocity checks closed off secondary exploit vectors as attackers probed for weaknesses.
Scalable cost structure. Enterprise flat-fee pricing kept costs manageable even during dramatic usage spikes.
What's next
Having proven the value of Abstract under real attack conditions, the team is now evaluating IP Intelligence for post-incident attack analysis and VPN detection in customer support workflows. They are also in discussions to move to an annual enterprise credit model, ensuring they have a volume buffer ready for the next wave whenever it comes.
This case study was produced anonymously at the customer's request. Operating in the cryptocurrency sector, the company maintains a strict security posture and does not publicly disclose the tools used in its fraud prevention stack.