ATO Attacks and How to Prevent Them

As businesses embrace technology and move their IT infrastructure to the cloud, account takeover fraud becomes a rising threat. SaaS applications like Salesforce, Office 365, or Zoom can never be protected using fixed security perimeters like firewalls. Unfortunately, they’re exposed to public networks. 
Organizations that adopt cloud solutions need to review how users are validated. Subsequently, it’ll reduce the risks of account takeover attacks (ATOs). Such threats have been around for decades and can cause severe damage to business continuity.
Want to protect your user accounts? Then keep reading this guide to prevent ATO attacks and keep your accounts safe. 

What are ATO Attacks?

An account takeover attack is a form of identity theft where a cyber actor gains access to a victim’s account. The main goal is to use stolen identities for selfish gains. Cybercriminals often target work-related accounts. Also, they buy user credentials from the dark web to access ecommerce, travel, finance, and social media sites. Afterward, they try to log in by testing hundreds of username and password combinations. When ATO attacks happen, a hacker can impersonate the user in several ways, including:
  • Committing payment fraud
  • Gaining access to sensitive data
  • Modifying or escalating a user’s privilege to access company resources
  • Sending out emails or other forms of communication to launch further attacks like Business Email Compromise (BEC)

What Organizations are Targets for ATO Attacks?

Financial institutions are a major target of ATO attacks. However, every institution that utilizes user-facing logins can become a victim. The primary goal of cyberattacks is usually financial gains. These include selling stolen data, stealing cryptocurrencies, or deceiving victims to install ransomware.
Personal Identifiable Information is also a target of ATO attacks. For example, cyber actors can use this information to carry out identity theft, like getting credit and debit information and committing insurance fraud.
Additionally, they can use personal details to make fraudulent messages look genuine. These types of attacks target academic institutions, healthcare, and public sectors.
ATO attacks are also a common threat to ecommerce and social media sites. Cyber attackers can hijack existing ecommerce accounts and buy items at the victim’s expense. Usually, the hacker takes over an ecommerce account, adds items to the cart, and pays using the victim’s stored payment details
A good example of an ATO attack is the coordinated campaign on Twitter in 2020. The breach compromised the Twitter accounts of rich and famous people like Jeff Bezos, Bill Gates, Elon Musk, Joe Biden, Kanye West, and others.  The attack promoted a cryptocurrency scam. The hackers gave their followers 30 minutes fooled them into sending them bitcoins. Of course, the money can’t be tracked or returned due to blockchain anonymity.

How Do Cyber Actors Execute Account Takeover Attacks?

Various methods exist for carrying out account takeover attacks. Below are the most common ones.

Phishing Attacks

A phishing attack is one of the most widespread forms of attack on the internet. Hackers send a link via email, chat conversations, scam websites, SMS, social media, and even a phone call. The victim clicks on the URL and either gets redirected to a scam website or begins a malware installation in the background. As a result, they end up giving cybercriminals access to their devices or share personal details.


Malware is a malicious program designed to gain unauthorized access to a victim’s device. When you download software from unfamiliar sites, you can unknowingly install malware on your device. This program can monitor everything you do on your device. The attacker will just wait for you to input your credentials. 

Credential Stuffing

Credential stuffing is a brute force attack that can lead to account takeovers. It’s where cybercriminals use stolen usernames and passwords on various sites. Credential stuffing is possible because most account holders re-use their passwords and usernames.
Cyber actors use bots to scan multiple account-based websites. They identify users and compromise their accounts. Many account holders fall victim to this attack due to poor password management and neglecting Multi-Factor Authentication (MFA)

Man-in-the-Middle Attack

A man-in-the-middle attack involves intercepting the communication link between two parties. Once an attacker gains access to your communication system, they can:
  • Listen to your conversation
  • Edit messages
  • Spy on you
  • Steal credentials and personal information
  • Block access to your account
The ramifications of such an attack can be severe. 

Account Takeover Prevention Measures

As you’ve seen, account takeovers can damage your business if no adequate preventive measures exist. Here are some ways to protect your organization from ATO attacks. 

Use Two- or Multi-Factor Authentication

Request your users and employees to activate Multi-Factor Authentication (MFA). MFA involves the use of extra factors to authenticate a user’s identity. These factors can include one or more of the following:
  • Facts: Ask for security questions such as their first pet name or nickname when creating their account
  • Identity: You can also encourage your users to protect their account using personal features like a fingerprint, face ID, iris scan, etc.
  • Possession: You can also incorporate a token or an OTP. 
You don’t have to request MFA from your users every time. Another location or device can be the trigger to start the authentication process.

Web Application Firewall

A Web Application Firewall (WAF) blocks HTTP traffic to protect web applications. WAFs can identify and block malicious access attempts. This measure can help prevent ATO attacks using one or more of the techniques below:
  • Discover and block requests from known cyber actors
  • Recognize credential stuffing on login portals
  • Identify attacker’s bot used for ATO attacks
  • Enforce MFA through third-party identity providers
  • Analyze traffic for “fingerprints” indicating credential stuffing tools

Privilege Management

When an account takeover happens, it’s crucial to decrease its impact. In most cases, account takeover is not the end goal. A cyber actor may want to access other sensitive organizational resources. If you already have a compromised account in the system, remove its access to assets and confidential data. Better yet, delete the user’s account altogether. Still, privilege management is more efficient as a preventative measure. One of the best ways is to enforce the least privilege principle. This regulation ensures that employees only have access to the resources they need to get their job done. Ensure there is a separation of duties to reduce the impact of an attack. 

Block Malicious Traffic

Cyber actors scan the network and port to learn about an organization’s network behavior and structure. Detecting network anomalies can help identify reconnaissance attacks. Usually, hackers use port scanning to learn about the resources you’re running on your organization’s networks.
You can use an IP lockdown to stop cyber actors from using stolen credentials. As a result, only authorized users will be able to connect to applications and access company resources. 

The Takeaway

As you can see, ATO threats are getting more sophisticated, from phishing and malware to credential stuffing and man-in-the-middle attacks. They can result in severe damages to business continuity. 
Detecting an account takeover attack can be challenging, though. Therefore, you should implement adequate preventive measures like two- or multi-factor authentication, web application firewalls, privilege management, and anomaly detection. This will help mitigate such threats and keep your business, employees, and private data safe.
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