There were more than 2,800 data breaches in 2024, including nearly 750 attacks on the financial services sector. Over 1.3 billion people had their information compromised. The direct financial damage from data breaches is bad enough, but the exposed information can also increase the risk of follow-up cyberattacks. Credential stuffing is one example, and it can hit enterprise-level businesses especially hard.
What Is a Credential Stuffing Attack?
Credential stuffing is an advanced type of brute-force password attack. Instead of testing randomized user IDs and common passwords, this method uses leaked or stolen credentials. Bad actors take pairs of credentials from a data breach and try them on as many different sites and systems as possible.
Credential stuffing does away with the randomization of traditional brute-force attacks. Real password and username combinations, even if they come from recognized data breaches, are more likely to succeed.
How Does Credential Stuffing Work?
Risk awareness is essential for avoiding password-based attacks. The better you understand how credential stuffing works, the more effective your defenses can be.
Purchased Credentials
Cybercriminals buy databases of usernames and passwords from past breaches cheaply on the dark web. Consider this: The 2013 and 2014 data breaches at Yahoo exposed the user information and passwords of 3.5 billion accounts. What if some of those users were also employees at Target, Wells Fargo, or a government agency?
Abusing ID and Password Combinations
Using automated tools, bad actors try the sets of IDs and passwords on every system they can get their hands on. Banks, retailers, healthcare organizations, manufacturing companies, and even small businesses may turn up a match. All is takes is one employee who uses the same password on multiple systems, and you’re vulnerable.
Bot Nets and Spoofed IPs
Instead of making hundreds of attempts from the same IP address, today’s attackers use an army of bots to spread logins out. To many system admins, it looks like normal network traffic.
Hybrid Stuffing
Some cybercriminals combine credential stuffing with social engineering attacks, like pretexting. Once they get an employee’s username, the attacker can keep trying brute force attacks even if you change the password.
Baiting is another tactic. Scam offers may not convince employees to give up work logins, but they may sign up for a new account. Knowing how the victim creates IDs and passwords (like DavidWhite1975) improves the chance of cyberattacks succeeding.
What Is the Difference Between Stuffing and Password Spraying?
Credential stuffing and password spraying work similarly, but they have differences in scale, methods, and targets.
Password Spraying: High-Volume Single-System Attacks
Password spraying attacks involve trying the same password with every account on a system. If bad actors get their hands on an enterprise’s user database, they can run random password guesses against thousands of IDs. Because the password is only attempted once per account, no lockout is triggered.
Credential Stuffing: Elusive Multi-System Attacks
With credential stuffing, hackers use ID and password pairings across multiple systems, such as CRM software, accounting tools, Microsoft 365 users, and so on. This approach makes it even harder for organizations to detect the attacks.
The attacks are spread out over time and on different systems, so admins are unlikely to see a pattern. Breach progress is slower but more dangerous because companies aren’t expecting it.
What Are the Warning Signs of Credential Stuffing Attacks?
Network and system monitoring is one of the best ways to prevent credential stuffing attacks. These advanced cybersecurity tools allow IT professionals to flag suspicious network traffic and track login patterns.
Abnormal Spike in Login Failures
To follow network security best practices, you should have a baseline for normal system usage, including traffic, logins, and downloads. Say the normal login rate is 1,000 users an hour. If that number jumps to 5,000 login attempts, there’s a good chance you’re under attack, even if the IPs are different for each.
High Volume of Login Failures in a Short Amount of Time
Instead of relying on the common “three strikes” per user to lock down the account, you can view logins from a wider lens. How many users per hour usually fail their logins? If the answer is 10 or 20, you know 1,000+ failures is a bad sign.
Bot Attacks
Some network security tools alert you when bot accounts are trying to log onto your system. The software has eyes on hundreds or thousands of organizations, so it notices when the same “user” tries and fails logins on dozens of sites in a short time.
How Do You Prevent Credential Stuffing?
Successfully repelling credential stuffing attacks requires a combination of strong password policies, cutting-edge tech, secure system configurations, and persistent training.
Test Passwords and Credentials
In addition to checking passwords against common databases, review them against flagged credentials on your own system. In other words, keep track of compromised passwords and don’t let anyone use them again.
Similarly, if an employee account is breached (or likely breached), change the user ID to something unique. Avoid following a predictable system for user IDs, especially personnel with admin access.
Use a Password Manager
Enterprise-level password vaults or personal password managers enhance login security immensely, especially if they have the ability to assign random passwords. These tools make it easier for employees to use long, complex passwords that are nearly impossible to guess.
Password managers also reduce the risk of employees using the same login for multiple services. The tool suggests the password instead of leaving it up to users.
Require Multifactor Authentication
In addition to defensive measures, you should also have credential stuffing mitigation tools in place, such as multifactor authentication. When your employees have MFA enabled, even if a credential stuffing attack succeeded, hackers still don’t have access because they need a physical device containing the authentication key to finish logging in.
Improve Your Defenses Against Credential Stuffing With Organizational Compliance
Credential stuffing exploits the inflexible nature and poor coordination of outdated IT security frameworks. The solution is to bring policies, work practices, and security controls into the modern era.
Compyl provides network monitoring, centralized data analytics, and risk tracking for enterprise organizations. Strengthen your defenses against credential stuffing, malware, ransomware, and other threats with Compyl’s AI-powered risk management tools. Request a demo to accelerate your organization’s progress toward cybersecurity maturity.
