Account takeover (ATO) fraud is a form of identity fraud where criminals use stolen or manipulated credentials to gain unauthorized access to an organization’s systems.

Unlike traditional fraud, which often relies on fake identities, ATO targets existing digital identities and exploits trust built into them, which can be hard to detect and may lead to far more severe consequences.

Driven by technological advancements and increasingly sophisticated threat actors, account takeover fraud is rapidly developing. To prevent it, organizations need a solution that can keep up without creating friction for legitimate users.

This article breaks down how account takeover (ATO) attacks unfold, the operational and financial risks they pose to organizations, and practical steps to strengthen your defenses through prevention and detection.

Key takeaways

• Organizations are increasingly exposed to stolen credentials through credential stuffing, phishing, malware, and other methods criminals use while trying to enter systems under legitimate user identities.
• Most account takeover incidents follow a predictable chain: credential compromise, unauthorized access, exploitation, and lateral movement.
• ATO usually hits organizational accounts of financial or strategic value. Account takeover is a larger threat today due to automation and the sheer volume of breached credentials circulating online.
• Corporate account takeover fraud often results in direct and indirect financial loss.
• Fraud solutions help organizations mitigate account takeover risk by embedding advanced fraud prevention and detection capabilities within the entire identity and access management lifecycle.

How account takeover fraud occurs

Criminals use multiple techniques to steal account credentials and bypass authentication so they are perceived as the legitimate users. These techniques often exploit different weaknesses depending on the target. In workforce environments, attackers typically take advantage of gaps in identity and access management (IAM) systems or human vulnerabilities inside the organization. In consumer scenarios, they may focus on the authentication process itself or manipulate the individual account holder directly through social engineering.

• Credential theft: Fraudsters steal login IDs and passwords by luring users to fake websites or sending malicious links asking them to provide credentials or install malware. To harvest the data, they use automated phishing kits and remote-access trojans. Stolen credentials then surface in dark web forums for sale to power further fraud. A single compromised password can give criminals a foothold deep inside an organization’s network.
• Phishing: This is one of the most common methods used to launch both consumer and corporate account takeovers. In consumer scenarios, attackers send emails or texts pretending to be a trusted brand or support rep, tricking individuals into clicking fake login pages or sharing credentials. In corporate ATO, phishing often targets employees, particularly those with access privileges, using lookalike domains or urgent messages to extract passwords or MFA codes. Phishing kits and automation have made it easier than ever for attackers to replicate login flows and harvest data at scale.
• Credential stuffing: In credential stuffing, criminals reuse large sets of credentials exposed in previous data breaches to automatically log in to corporate systems. They deploy botnets and scripts to inject millions of login-password combinations, looking for those that authenticate. It’s a volume attack that targets employee and customer accounts at scale.
• Brute force attacks: A brute force attack relies on systematic trial and error to guess login information on specific accounts. Unlike credential stuffing, it doesn’t assume prior knowledge of the password and depends on weak credentials. Fraudsters try different combinations of credentials in an attempt to find the one that works. If an organization allows weak passwords or lacks multi-factor authentication (MFA), these broad attacks can succeed.
• Man-in-the-middle (MITM) attacks: Man-in-the-middle attacks are a type of cyberattack where the hacker intercepts two parties (for example, business and consumer) who believe they are communicating with one another. In reality, attackers intercept information shared between the victim’s computer and a server. They can then eavesdrop on the information shared and use it to their advantage, such as redirecting victims to a spoofed website. Most MITM attacks occur on public Wi-Fi because connections are generally less secure than home routers.
• Social engineering and call center fraud: In corporate ATO, attackers may impersonate an employee and trick internal support staff into resetting credentials or bypassing security controls, no malware required. Once inside, they can disable monitoring tools or create persistent backdoor access. On the consumer side, fraudsters flip the tactic: they impersonate a company’s support staff to deceive users into revealing login credentials or account recovery details. This can happen through fake tech support calls, phishing, or even romance scams that build trust before exploiting it. The FBI’s Internet Crime Report recorded government impersonation losses of $405 million in 2024.
• Malware: This ATO fraud tactic involves deploying malicious software, such as banking trojans or spyware, to steal credentials by capturing keystrokes or hijacking sessions. Software like this can be spread via malicious links, infected USB drives, phishing emails, or drive-by downloads. According to the European Union Agency for Cybersecurity (ENISA), from January 2023 to June 2024, malware incidents affected 36% of credit institutions and 24% of individuals.
• SIM swapping: This is a method where a user’s phone number is transferred to a different SIM card or eSIM profile under the control of a criminal, allowing them to bypass two-factor authentication and gain unauthorized access to other corporate accounts linked to that number.

These techniques, however, are only the tip of the iceberg. Fraud trends evolve continuously, powered by emerging tech, especially quantum computing, which is expected to render today’s cryptographic methods obsolete. The transition to post-quantum cryptography might take several years, so it’s important that organizations start preparing now.

Account takeover fraud process

Here’s how a successful ATO attack usually unfolds:

1. Targeting: Fraudsters begin by identifying valuable accounts to compromise, either corporate or individual. In workplace scenarios, attackers may scan company websites, LinkedIn profiles, or employee directories to build a target list of staff with privileged access. Excessive public exposure of employee information or unprotected login portals makes this easier. On the consumer side, attackers might focus on bank customers, gathering leaked credentials from dark web marketplaces or social engineering their way into personal accounts.
2. Credential harvesting: Obtaining a target user’s login information through phishing, social engineering, malware, or any other method mentioned in the previous section. Weak or reused passwords and a lack of multi-factor authentication are big gaps here.
3. Account access and validation: Attempting to log in to the target account, including MFA/2FA bypass, if needed. Organizations failing to monitor account changes are at risk.
4. Privilege escalation: Leveraging the stolen credentials to access linked corporate accounts in the case of corporate ATO fraud, or an individual’s account in the case of consumer ATO fraud.
5. Exploitation and fraudulent transactions: Using the account to transfer money to mule accounts, buy goods, harvest personal data for further fraud, or change linked information so that the legitimate owner loses access without being able to recover it. Without robust auditing and incident response management, an organization might not even detect the issue.
6. Lateral movement and persistence: Using the compromised account to get deeper into the organization’s network and creating backdoor admin accounts or installing credential stealers to exploit future user sessions.

Consequences of account takeover fraud

For enterprise and financial institutions, the impact of account takeover attacks can be severe and multifaceted:

• Financial losses: Direct monetary loss is a primary consequence. Attackers may steal funds from corporate accounts or trick the organization into sending payments. If customer accounts are compromised, the business often bears the cost of fraudulent purchases and subsequent chargebacks. Banks and financial institutions are obliged to reimburse defrauded customers. There are also indirect financial hits, such as incident response expenses and forensic investigations.
• Operational and productivity costs: Account takeover often results in credential resets, account suspension, forensic investigation, and dispute processing, all leading to interruptions in operations that can’t go unnoticed.
• Reputational damage and customer trust: With customers expecting top-notch protection of their financial and private data, account takeover attacks can significantly damage brand trust, causing bad publicity, customer churn, and lost business and partnerships. The stakes are high: research shows 56% of consumers would switch banks if they or someone they know experienced fraud, and 55% believe their bank could do more to protect them.
• Legal and compliance liability: When private information is exposed or service terms are violated, organizations face legal responsibilities and potential regulatory action. Failure to ensure proper data security can be seen by regulators as negligence under General Data Protection Regulation (GDPR) and similar laws.

Account takeover fraud targets

ATO can hit virtually any account with financial or strategic value. Notable account takeover examples across industries include:

• Healthcare accounts: Hospitals and clinics face not only the theft of funds or data in an account takeover but also potential HIPAA violations, regulatory fines, loss of patient trust, and disruption of operations (imagine critical systems locked or manipulated by an intruder).
• Financial accounts: A successful takeover of a financial account can enable fraudulent wire transfers, unauthorized withdrawals, or new lines of credit, often resulting in direct monetary loss and potential liability or reputational damage for the institution if customers aren’t protected.
• Retail and e-commerce accounts: The fallout from such takeovers includes fraudulent orders made on victims’ stored credit cards and theft of gift card balances, both directly hitting the merchant’s revenue and undermining customer trust.
• Corporate and service accounts: Corporate account takeover is an emerging threat where cybercriminals gain unauthorized access to an organization’s financial or administrative accounts and once inside, initiate fraudulent wire transfers or steal confidential data.

Enterprise ATO is increasing. The 2024 State of Cloud Account Takeover Attacks showed that in 2023, 83% of organizations experienced at least one account takeover. ATO incidents pose tremendous reputational, financial, and operational risks to organizations, becoming an identity security issue, not just a customer-service problem, and prompting them to deploy fraud detection capabilities that are up to the task.

In the consumer space, different types of businesses face higher rates of account takeover fraud dependent on their product offering. For example, in the payments industry, 82% of fraud occurs after onboarding and is linked to ATO fraud. For banks, 55% of fraud occurs after onboarding and is linked to account takeovers. In contrast, businesses like crypto see most fraud during onboarding (67%). This highlights the importance of having a strong solution in place throughout the customer lifecycle.

Detecting and preventing account takeover fraud

In organizations, ATO fraud doesn’t manifest as one big, obvious alert. Rather, it shows patterns: strange login patterns, abnormal user activity, unexplained credential or profile changes, multiple access failures, and direct reports of anomalies. The urgency to act is clear – according to new research, 84% of consumers say better fraud protection represents a better service experience, and 79% are willing to complete additional verification steps if it improves their long-term safety.

Early detection can dramatically reduce damage. It requires a multi-layered account takeover prevention strategy with the following core elements:

• Strong authentication: This is usually the first line of defense, which boils down to implementing multi-factor authentication for both internal and customer-facing accounts so that stolen passwords alone are not enough to break in. However, attackers have developed tactics to bypass certain forms of MFA. Where feasible, organizations should aim for phishing-resistant MFA, including FIDO2/WebAuthn security keys or tokens, hardware smart cards, or platform authenticators that perform device-local biometric or PIN verification. Push-based authenticators with number matching also can improve security. Biometric verification methods, like facial recognition or fingerprint scanning, which are difficult for fraudsters to replicate, adding a strong defense against unauthorized access. In fact, according to Entrust research, 35% of consumers rank biometric authentication as the most trusted login method – higher than passwords (22%) and one-time passcodes (18%) – and 68% say they’re happy to use biometrics if it offers better protection.
• Trigger real-time notifications: Set up automated alerts to notify customers of suspicious activities, such as login attempts from unfamiliar locations or changes to account information, prompting them to take immediate action.
• Continuous monitoring and anomaly detection: Organizations should adopt systems that track user behavior and transactions in real time, rather than relying solely on log reviews. This way, they can catch when something deviates from the norm. Monitoring should be paired with risk-based authentication (RBA), which scores each login for risk based on factors such as location, time, user behavior, and more. Device identification, coupled with geolocation, can recognize known devices and spot new ones.
• Advanced fraud detection tools: Based on large volumes of login and transaction data, organizations can train models to know what “normal” looks like for each user and assign a risk score to each session as it happens. AI can also predict which accounts are at higher risk.
• Employee education: Regularly educating users about account takeover prevention is as important as implementing the right technology with fraud detection capabilities. Employees should know how to spot phishing and phone scams. They should be taught to escalate anything suspicious to the security team right away.

Identity verification continues to evolve as threats like social engineering and device emulation accelerate. This shift is transforming IDV and organizations worldwide are responding with smarter, scalable solutions. Discover key fraud trends and insights to help you protect identity and maintain trust in a digital-first world.

How Entrust helps organizations protect against account takeover fraud

To fight successfully against unauthorized access and identity theft causing billions in losses, organizations need a comprehensive suite of identity verification solutions that leverage next-gen technology and principles of Zero Trust to ensure appropriate access to corporate resources and verify identities at account creation.

Account takeover fraud doesn’t follow a script, so defense can’t rely on static rules. Entrust brings together identity, risk signals, and behavior analytics to spot threats during logins or account creation, without blocking trusted users. Risk is evaluated in real time, so access decisions adjust automatically based on context. Our identity-first approach uses biometric verification, official IDs, and trusted devices to confirm who’s behind the screen.

Learn more about how Entrust’s AI-powered fraud prevention solutions help organizations integrate fraud detection into every stage of the identity and access management lifecycle.

FAQs

What is account takeover fraud?

ATO occurs when an attacker uses stolen or manipulated credentials to log in as a legitimate user inside your organization. Fraud prevention solutions such as Entrust can help organizations mitigate risk by pairing phishing-resistant MFA and adaptive authentication with device/behavior analytics.

What are the different types of account takeover fraud?

Common ATO types include credential theft, credential stuffing, brute force attacks, social engineering, call center fraud, malware, and SIM swapping.

What is the difference between an account takeover and identity theft?

ATO is about stealing an existing account; identity theft relies on stealing personal data to open new accounts.

What are examples of account takeover?

Examples include attackers taking over employee or customer accounts to move funds, steal data, or impersonate legitimate users.

How can account takeover be detected?

ATO can be detected through specialized software with fraud detection capabilities — by tracking anomalies such as unusual login activity (failed attempts or new IPs/devices), unexpectedly large transactions, or sudden account changes (password/email resets).