Corporate Account Takeover: How it works & tips for prevention

Corporate account takeover (CATO) is a growing threat that allows cybercriminals to gain unauthorized access to business accounts, leading to financial fraud, data breaches, and operational disruptions. Attackers use tactics such as phishing, credential stuffing, and malware to compromise employee or executive accounts, often moving laterally within the network to escalate privileges and exfiltrate sensitive information. With stolen credentials frequently sold on the dark web, businesses of all sizes are at risk.

This blog delves into how corporate account takeovers happen, the tactics attackers use, and the impact on organizations. More importantly, we’ll explore best practices for prevention, including strong authentication policies, continuous monitoring, and user awareness training.

What is corporate account takeover?

Corporate account takeover (CATO) is a type of cyberattack in which a cybercriminal gains unauthorized access to a company’s employee account, often through stolen login credentials or malware, and uses that identity to carry out fraudulent activities while avoiding detection. What sets corporate account takeover apart from regular account takeover is its focus on business or enterprise accounts, often with elevated privileges or access to sensitive systems.

Because the attacker is operating under the identity of a trusted employee, their actions often go unnoticed, allowing them to access sensitive data, perform unauthorized transactions, or move laterally through internal systems. This can lead to significant financial loss and data breaches, as the attacker effectively inherits the permissions and access rights of the compromised user.

How does an account takeover attack work?

Corporate account takeover attacks typically follow a multi-stage process. Once a cybercriminal gains initial access to a business account (often through stolen credentials) they aim to deepen their access and ultimately exploit it for financial or strategic gain. Here’s a breakdown of how these attacks usually unfold:

1. Initial compromise

The attack begins with the cybercriminal gaining unauthorized access to a single user account — often that of an employee or third-party vendor. Common access methods include phishing, credential stuffing and malware deployment. This first foothold gives the attacker access to internal systems using a legitimate user identity, making their activity less likely to be flagged by automated security tools.

2. Escalation & lateral movement

Once inside the network, attackers rarely stop at the initial account. Instead, they aim to expand their access to higher-value systems and data.

• Privilege escalation: The attacker tries to increase access rights by exploiting system misconfigurations, unpatched vulnerabilities, or over-permissioned accounts.
• Lateral movement: The attacker navigates the internal network, using legitimate credentials or stolen session tokens to compromise additional accounts or systems.

This stage is especially dangerous because the attacker is still operating under the guise of a legitimate user. Without advanced detection measures, their actions can blend in with normal business activity.

3. Exfiltration or abuse

Once the attacker has reached their target, whether that’s financial systems, intellectual property, or customer data, they take one or more actions:

• Data exfiltration: Sensitive documents, credentials, or databases are quietly transferred to external servers controlled by the attacker.
• Financial fraud: If the attacker gains access to payment systems or finance software, they may initiate wire transfers or divert funds.
• Ransomware deployment: In some cases, attackers may deploy ransomware at this stage to encrypt critical data and demand payment.
• Destructive actions: Some attackers delete logs, disable security tools, or destroy backups to cover their tracks or maximize impact.

At this point, the organization may start noticing signs of compromise, such as unusual activity, failed logins, or unauthorized transactions — but the damage may already be done.

Top techniques used in corporate account takeovers

Bad actors use various tactics to establish an initial foothold in the environment they’re targeting. By taking over an account, the attacker has an opportunity to act as that user, download sensitive information that the compromised account has access to, pivot to other systems, and elevate privileges. 

Here are some of the most common methods attackers use to gain access to corporate accounts:

1. Social engineering 

Have you ever received a phone call where you knew the individual on the other end was not authentic? How about an email with an attachment or link that was illegitimate? If you’re unable to answer “yes” to these questions, you’ve likely fallen victim to social engineering. This human-based attack vector exploits the decision-making process by influencing a person to act in a certain way. Often, these attacks require less time and effort than exploiting system vulnerabilities.  

2. Phishing attacks 

Phishing is a social engineering technique used by attackers wherein they attempt to get hold of sensitive information (e.g. login credentials) using fraudulent email communications that appear to originate from an authentic source. Attackers use phishing to take aim at unsuspecting victims using creative methods to disguise their communications. 

Targeted phishing attacks have become more common with the widespread use of social media. With the enormous amount of public information available on social media platforms, attackers can heavily customize phishing attempts to the victim’s interests and emotions, which increases the likelihood of exploitation. These heavily targeted attempts are known as spear phishing. These communications are tailored to the victim, keying on their interests and emotions to bate them into providing sensitive information or executing malicious code. 

3. Password attacks 

What can you find about yourself on the internet? Can you see your password on your social media account? How about in the “about” section of your Facebook page? People tend to formulate passwords that are easy for them to remember. Favorite food, favorite sport, favorite season, and maiden name are a few common examples that people use to model their password.

Even complex passwords can be insecure, as people often reuse the same password across multiple platforms. If one platform is compromised and the individual’s password is obtained, it can be used to authenticate elsewhere. For these reasons, single-factor password-based authentication tends to be weak and risky. 

4. Brute force attacks 

Brute force attacks attempt to uncover a password by guessing all possible combinations. The time it takes to crack a password is largely dependent on the password’s complexity and predictability and the resources (e.g. computing power) at the attacker’s disposal. Malicious doers often use public sources (e.g. social media accounts, business websites, etc.) to gather intelligence on their targets, developing a list of dictionary words.

They then use password cracking tools to automate guessing attempts based on the list of words, trying all possible combinations. This variant of brute force attack, known as a dictionary attack, assumes that the target uses some variation of dictionary word and can decrease the time and effort that it takes to successfully brute force a user’s password. 

5. Credential stuffing 

As previously stated, people tend to use the same password across multiple platforms. Why is this dangerous? Well, cyber breaches have become a common occurrence. Credential stuffing attacks use the information obtained from previous breaches to inject username and password combinations to gain access to a target’s account. 

How to prevent account takeover attacks 

Corporate account takeover attacks can result in severe consequences — ranging from financial loss and operational disruption to reputational damage and regulatory penalties. While it’s important to acknowledge that no system can ever be 100% secure, organizations can significantly reduce their risk exposure by adopting a layered defense strategy and fostering a culture of security awareness.

Here are key practices that can help prevent account takeover incidents and mitigate their impact:

1. Apply the principle of least privilege 

In today’s threat landscape, organizations must operate under the assumption that attackers will find a way in. That’s why limiting what an attacker can do post-compromise is crucial. One way to limit this impact is to prioritize the principle of least privilege, where the focus is on supplying users and programs with the minimum level of access necessary to perform their duties — and nothing more. This supports the “never trust, always verify” vision of a Zero Trust Architecture. 

If an attacker gains access to an account with excessive permissions, they can do a significant amount of damage. By enforcing the principle of least privilege, organizations limit lateral movement, making it harder for attackers to escalate privileges or access sensitive resources.

2. Enforce strong password policies

Despite the rise of phishing and malware, weak or compromised passwords remain one of the most common ways attackers gain initial access to corporate accounts. Enforcing a strong, modern password policy is a key step in preventing account takeover. This should include:

• Minimum length and randomness: Require passwords to be at least 12–14 characters and encourage passphrases (e.g. PurpleCarrot$Jumping9).
• Banned password lists: Prevent the use of common, guessable, or previously breached passwords by comparing them against known compromised password databases.
• No password reuse: Prevent users from reusing passwords across rotations.

By enforcing a robust password policy, you shrink the attack surface and make it exponentially harder for unauthorized users to gain a foothold.

3. Implement Multi-Factor Authentication (MFA)

An organization that enforces Multi-Factor Authentication reduces the risk of credential compromise by layering protection. MFA requires users to provide two or more forms of verification before accessing an account; typically a password (something you know) and a secondary factor, such as:

• A time-based one-time password (TOTP) from an authenticator app
• A biometric factor (e.g. fingerprint or facial recognition)
• A hardware token or smart card

Even if attackers obtain valid login credentials (via phishing, data breach, or brute-force attacks), MFA prevents unauthorized access unless they also possess the second authentication factor.

4. Secure and monitor third-party integrations

Companies are rapidly shifting towards more and more cloud-based environments, meaning most — if not all — are relying on third-party tools and software. These third-party vendors, SaaS tools, and APIs often have access to sensitive systems or data. If their credentials or tokens are compromised, attackers can bypass many of your direct controls.

To secure third-party access, you should:

• Maintain an inventory of all third-party apps and integrations that have access to internal systems or data
• Use OAuth token management to monitor which apps are authorized and revoke unnecessary or unused tokens
• Require vendors to use MFA and follow secure development practices
• Always keep third-party software and tools up to date with the latest patches to reduce the risk of known vulnerabilities being exploited by attackers

5. Require employee awareness & training 

Humans remain one of the weakest links in cybersecurity. Attackers exploit human error through phishing, social engineering, and credential reuse. Even with strong technical controls, poor user decisions can open the door for compromise. Common risky behaviors include:

• Reusing the same password across multiple (or all) accounts
• Storing passwords in unsecured formats (e.g. spreadsheets or sticky notes)
• Clicking links within emails before verifying the sender of the email and authenticity of the link 
• Trusting unsolicited requests for credentials or assistance

Well-designed awareness programs educate users on how to identify phishing attempts, use secure authentication methods, and follow safe browsing and email practices. Training should be continuous, relevant, and include real-world simulations to reinforce learning.

Stop corporate account takeover at the source

Stolen credentials are one of the most common entry points for corporate account takeover attacks, and even strong passwords aren’t immune. Specops Password Policy continuously scans your Active Directory for over four billion known compromised passwords, alerting users and forcing immediate resets when breaches are detected.

Don’t let exposed credentials become the doorway to your next security incident. Get in touch today for a free trial and start protecting your organization against credential-based attacks.

Frequently Asked Questions