Account Takeover (ATO) Attacks

Imagine logging into your organization’s bank account only to find that all the money’s gone.

Or finding out that a hacker broke into your CFO’s email and sent fake invoices, tricking customers into wiring money to a fraudulent account.

That’s the terrifying reality of Account Takeover (ATO) attacks, where hackers gain unauthorized access to your online accounts and wreak havoc.

Whether it’s financial accounts, corporate emails, or even internal collaboration tools like Slack, ATO attacks can result in massive financial losses, reputational damage, and even legal liabilities.

For any organization, losing control of key accounts is more than just an inconvenience — it directly affects your bottom line.

Let’s break down what ATO attacks are, how they happen, and what you can do to protect yourself.

What are Account Takeover Attacks

An account takeover attack occurs when a cybercriminal gains unauthorized access to a user’s online account — usually by stealing login credentials.

Once in, the attacker can do anything from stealing your money, impersonating you, or using your account to launch other scams.

Why do they do it? Simple: It’s profitable. The goals of ATO attacks often include:

Financial Theft: Stealing money from bank accounts or making fraudulent purchases.
Identity Theft: Using your personal information to open new accounts or commit other types of fraud.
Reputational Damage: Posting harmful content on your social media or sending emails under your name.
Launching Further Attacks: Using your compromised account as a foothold to infiltrate your network or trick your contacts.

How Do Account Takeover Attacks Happen?

Hackers aren’t magicians—they rely on a various of techniques to gain access. Here’s how they usually do it:

1. Data Breaches

What It Is: Unauthorized access to large amounts of data from companies or services.
How It Works: Stolen usernames and passwords from one breach are often sold on the dark web. Attackers buy these credentials and try them on multiple platforms, hoping that people reuse passwords.

2. Malware

What It Is: Malicious software designed to infiltrate and damage systems.
How It Works: Once installed on your device, malware can capture keystrokes, take screenshots, or even directly grab saved passwords.

3. Credential Stuffing

What It Is: Using stolen username and password combinations from data breaches to gain unauthorized access.
How It Works: Attackers use automated tools to try these credentials on multiple websites, hoping that people reuse the same passwords.

4. Phishing

What It Is: Fake emails, messages, or websites designed to trick you into entering your login info.
How It Works: You think you’re logging into a legit site, but you’re really handing your credentials straight to the attacker.

5. Brute Force Attacks

What It Is: Systematically guessing passwords until the right one is found.
How It Works: Automated software rapidly tries different combinations, especially targeting weak or commonly used passwords like “password123.”

What It Is: Manipulating people into giving up confidential information.
How It Works: Attackers might pretend to be a friend, co-worker, or service provider to trick you into revealing your credentials.

7. Exploiting Weak Security Practices

What It Is: Gaps in security practices that attackers exploit to gain access.
How It Works: Examples include using default passwords, lack of multi-factor authentication (MFA), or failing to update software with security patches.

What Type of Accounts Are Most Often Targeted?

Some accounts are more attractive to attackers due to the high value of information they have access to or the potential for financial gain. Here’s a breakdown of the most targeted types of accounts:

1. Financial Accounts

Bank Accounts: Direct access to your money.
Credit Card Accounts: Fraudulent purchases and cash advances.
Online Payment Systems: PayPal, Venmo—anywhere there’s money to be moved.

2. Email Accounts

Personal Email: Can be used to reset passwords for other accounts.
Corporate Email: Leads to business email compromise (BEC), where attackers pose as executives to scam employees.

Personal Social Media: Used for identity theft or spreading misinformation.
Influencer Accounts: High-profile accounts are valuable for scams or spreading malicious links.
Corporate Social Media: Damaging a brand’s reputation or promoting phishing scams.

4. E-commerce Accounts

Shopping Accounts: Amazon, eBay—where attackers can make unauthorized purchases.
Subscription Services: Accessing streaming or subscription accounts to resell.

5. Healthcare Accounts

Patient Portals: Exposes sensitive medical information.
Insurance Accounts: Potential for medical identity theft or submitting fraudulent claims.

6. Gaming Accounts

Online Gaming Platforms: Virtual goods, payment info, personal data.
In-game Accounts: Virtual currencies and items can be stolen and resold.

7. Cloud Storage Accounts

Personal Cloud Storage: Sensitive documents, photos, and other private files.
Corporate Cloud Storage: Intellectual property, business documents, and customer data.

8. Professional Accounts

Workplace Tools: Slack, Teams—gathering sensitive business info or furthering internal attacks.

Real-World Examples of Account Takeover Attacks

1. Twitter Bitcoin Scam (2020)

High-profile accounts, including those of Elon Musk, Barack Obama, and Bill Gates, were hijacking via social engineering, allowing attackers to promote a Bitcoin scam that netted over $100,000 before being shut down.

2. Uber Data Breach (2016)

Hackers accessed Uber’s GitHub repository and used leaked login credentials to steal personal data of 57 million users and drivers.

3. Robinhood (2020)

Nearly 2,000 accounts were compromised due to weak credential security, allowing attackers to siphon funds and make unauthorized trades.

How To Prevent Account Takeover Attacks

Stopping ATO attacks requires a combination of technical controls, security policies, and user awareness. Here’s what you can do to keep your accounts safe:

1. Implement Multi-Factor Authentication (MFA)

Adds a second layer of security, like a text code or biometric scan, making it harder for attackers to get in even if they have your password.

2. Use Strong, Unique Passwords

Avoid using the same password across multiple accounts. Use a password manager to generate and store complex passwords.

3. Regularly Monitor and Audit Accounts

Keep an eye out for unusual login patterns or changes. Use tools like SIEM and User Behavior Analytics to identify suspicious activity.

4. Educate Users on Phishing

Train users to spot phishing attempts and always verify suspicious communications.

5. Implement Account Lockout Policies

Temporarily lock accounts after several failed login attempts to prevent brute force attacks.

6. Deploy CAPTCHA Challenges

Use CAPTCHA to block bots from automating login attempts.

7. Enable Account Alerts

Set up notifications for unusual activities like password changes or logins from new devices.

8. Adopt Zero Trust Security Model

Trust no one—inside or outside the network. Continuously verify identities and limit access.

9. Use Dark Web Monitoring

Continuously monitor for exposed credentials on the dark web and force password resets when they’re found.

10. Regularly Update Software

Keep all systems up to date to prevent attackers from exploiting known vulnerabilities.

Final Thoughts

Account takeover attacks are a growing threat, but they’re not unbeatable.

Implementing dark web monitoring, quickly shutting down phishing sites and reseting leaked passwords and session tokens can go a long way in preventing ATO attacks.