Account takeovers happen when cybercriminals steal login credentials to access an email account. If a malicious actor successfully compromises an account, they can use it to commit fraud, send phishing emails, steal data, and more.
Account takeover fraud happens when cybercriminals gain legitimate login credentials and then use those credentials to send more attacks from a trusted account. Sometimes these account takeovers deal with financial information, but they also work to steal sensitive data.
To prevent account takeovers (ATOs), companies need infrastructure to protect themselves from credential phishing and business email compromise (BEC) attacks that often lead to these email account takeovers.
Even though fraudulent account schemes are a significant threat, preparing for them and mitigating most risks is definitely possible.
Let's look at the definition of email account takeover fraud, how an ATO typically happens, and what steps you can take to prevent account takeover for your company.
Account takeover is a term that describes business identity theft that occurs when a bad actor uses an employee's credentials for a malicious purpose.
One of the main reasons why email account takeovers are hard to eliminate is that they take many forms. Attackers constantly look for vulnerabilities in enterprise companies, as even a single successful account fraud instance provides significant rewards.
They do this through credential phishing, brute force attacks, password spraying, and various other methods. Even though the approaches are different, they can all successfully compromise an account.
Account takeovers unfold in a series of calculated steps, whether the compromised account belongs to a trusted vendor or an internal employee.
Here's how attackers typically execute these threats:
Most account takeovers begin with a deceptive email. The attacker crafts an email that appears to come from a legitimate source, often mimicking a known vendor, financial institution, or internal colleague.
In many cases, attackers use broad phishing tactics like social engineering to cast a wide net, tricking recipients into clicking malicious links or entering credentials on a spoofed login page.
More dangerous attacks start with spear phishing to get sensitive information. It’s a targeted form of attack that impersonates a known contact or business partner and includes personalized details to appear credible. These messages often mirror prior conversations, use familiar language, and include a sense of urgency, making them especially difficult to detect.
In some cases, the emails deliver malware that logs keystrokes or installs backdoors into the system.
Once the attacker obtains valid credentials, they log in to the account.
To remain undetected, they may set up forwarding rules, delete alerts, and begin monitoring communications. At this stage, the attacker gains full access to sensitive information, communications, and potential financial workflows.
Once inside, the attacker spends time understanding the victim’s workflows. They observe how invoices are sent, who approves payments, and which vendors or departments handle financial transactions.
This step allows them to identify the right moment and the right person to target for maximum impact.
Using insights from reconnaissance, the attacker crafts a believable email designed to manipulate the recipient into transferring funds or updating payment details.
There are two common forms of account takeovers: third-party account takeovers and internal account takeovers.
In third-party account takeovers, also known as vendor email compromise, threat actors send a fraudulent invoice from a real vendor’s account or impersonate a supplier to redirect payments.
Here's how a typical attack can occur:
The victim receives a typical email from a vendor that uses the same format and language as their previous interactions.
The email states that payment details have been updated and that future transfers should be made into a different account.
The victim makes a payment using the fraudulent account.
In internal account takeovers, the attackers pose as a CFO or payroll manager to initiate unauthorized transfers. Because the messages appear legitimate and align with existing patterns, these messages often bypass both technical defenses and human intuition.
Preventing vendor email compromise, internal account takeovers, identity theft, and other attacks from occurring is possible with the right cybersecurity infrastructure and security awareness training.
If undetected, the attacker may remain in the environment to repeat the fraud, target additional accounts, or exfiltrate sensitive data.
In other cases, they execute a single transaction and disappear, leaving behind financial losses and reputational damage. Either outcome highlights the critical need for proactive detection and behavior-based threat analysis.
Preventing account takeovers starts with preparation and succeeds with layered defense. While attackers continue to evolve their tactics, organizations can stay ahead by combining user education with advanced security technology.
Begin by equipping employees with the knowledge to recognize and resist threats. Anyone with access to sensitive information should be trained to use security tools effectively and identify signs of phishing and social engineering.
Ongoing education is key, especially as attacks become more personalized and deceptive.
Key steps to train your employees include:
Training employees to recognize phishing and social engineering
Reinforcing the need to verify unusual financial or data requests
Ensuring proper use of security tools already in place
Updating internal policies as threat tactics evolve
But awareness alone isn’t enough. Sophisticated threats often bypass legacy defenses, which underscores the need for modern, AI-native solutions that detect anomalies in behavior and communication patterns.
Abnormal provides complete protection against internal and third-party account takeovers. By leveraging behavioral AI, the platform automatically identifies and blocks suspicious activity, stopping threats before they reach inboxes. Whether it’s a spear phishing attempt or a compromised vendor account, Abnormal ensures your organization stays secure.
Schedule a demo to see how Abnormal can help prevent email account takeovers.
