USE CASE

Account Takeover (ATO) Prevention

Stop automated credential-stuffing and AI-driven ATO with real-time visibility, behavioral detection, and active defense across your APIs.

In an era where APIs drive most digital interactions, businesses face growing pressure to secure authentication flows and protect sensitive user data. Account Takeovers occur when an attacker gains unauthorized access to a legitimate account to steal data, make fraudulent purchases, or use the compromised account to launch further attacks.

How ATO Attacks Work

Harvest Credentials

Collect usernames and passwords from data breaches, dark web marketplaces, phishing campaigns, or malware-infected systems.

Automate Attacks

Launch credential stuffing or brute-force attacks, using botnets to iterate thousands of login combinations against APIs and login portals.

Exploit Weaknesses

Collect weak or reused passwords, authentication misconfigurations, and endpoints lacking proper rate limiting to validate compromised accounts.

Monetize Access

Theft through financial fraud, loyalty points, fraudulent transactions, or resale on underground forums.

CASE STUDY

Poshmark Prevents Automated Account Takeover Fraud with the Cequence Unified API Protection Solution

Agentic AI is Transforming ATO

Agentic AI has raised the stakes for account takeovers. Unlike traditional bots with static rules, AI-powered bots adapt in real time—rotating device fingerprints, modifying headers, and mimicking human behavior to evade detection. They analyze error codes and lockout policies on the fly, shifting strategies to bypass defenses and even exploiting MFA through token theft or reverse proxy phishing. Some use adversarial machine learning to probe fraud models. Combined with AI-driven phishing, deepfakes, and chatbots, these techniques make ATO attacks faster, stealthier, and far more effective.

Impacts of ATO

Account Takeovers are ranked #2 in the OWASP API Security Top 10, and create cascading financial and operational impacts. Businesses face financial losses from fraudulent transactions, chargebacks, and remediation efforts. Customer support teams can become overwhelmed handling account recovery requests and fraud disputes, resulting in operational strain. Perhaps more damaging, organizations risk losing long-term customer trust, which can lead to churn after a high-profile incident.

Real-World Examples

PayPal

Large‑scale credential stuffing attack tested reused passwords via automated bots against API flows, highlighting weak defenses against API-based brute force.

Roku

15k+ accounts compromised using stolen third‑party credentials, with profiles resold on dark web markets to stream content fraudulently.

Chick-fil-A

Rewards account infiltration via credential stuffing bots, with balances resold—highlighting loyalty program abuse.
Learn more about loyalty program abuse

How Cequence Prevents Account Takeovers

Cequence helps organizations discover and prevent account takeover attacks with the Unified API Protection (UAP) platform which employs a network-based approach to discover APIs, document their behavior, understand data flows and business context, and block attacks.

Discovery & Inventory

Cequence discovers login and other APIs that may be targeted by ATO attacks and develops an inventory including automatically creating API specs if they don’t currently exist. The comprehensive inventory provides visibility and understanding of the API behavior necessary to detect and prevent malicious activity.

Behavioral Fingerprinting (ML)

Cequence utilizes behavioral fingerprinting to group similar API transactions based on combinations of characteristics including the tooling used (such as browser type and version), infrastructure (such as proxies), and credentials, and employs ML to analyze behavior and accurately identify malicious behavior. Cequence can accurately detect both high-volume and low-and-slow attacks and can track attacks even as they evolve to avoid detection.

Additional Resources

Financial Services Customer Stops Millions of ATO Attacks

What is Account Takeover (ATO)?

Find out how Cequence can help your organization.

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