Account Takeover (ATO): A Practical Guide to Finding and Preventing Attacks

Account Takeover (ATO) is a critical cybersecurity threat where an attacker gains unauthorized access to a user’s account. This can happen through:

✅ Leaked credentials (Data breaches, phishing, keylogging)
✅ Weak authentication mechanisms (No multi-factor authentication, session hijacking)
✅ Session hijacking and cookie theft
✅ Brute-force attacks (Credential stuffing, password spraying)

Once attackers gain control, they can steal sensitive information, make unauthorized transactions, or escalate privileges to access critical systems.

In this article, we will cover:

🔹 How attackers exploit ATO vulnerabilities
🔹 Practical techniques to test for ATO in bug bounty & penetration testing
🔹 How to secure applications against ATO attacks