Everything You Must Know About Credential Stuffing

As a result of a wide range of malware, spam, ransomware attacks, phishing drives, and other hacks, cyberattacks have reached an all-time high, affecting businesses and individuals of all sizes.

We often come across several online accounts that have hacked on digital networks, even though the organizations claim that their systems have not hacked.

What makes that even possible? It is because of a thriving hacker procedure called credential stuffing.

What is credential stuffing?

Credential stuffing is a simple strategy in which hackers collect usernames and passwords from organizational breaches and attempt to stuff them into various other digital media outlets. 

In this case, attackers take advantage of several users to exchange passwords across different digital channels or pages. 

Credential stuffing is also being used by hackers to secretly access users’ personal information and accounts using these credentials.

Credential stuffing is a type of cyberattacks can use for everything, like spamming, phishing which can lead to the installation of ransomware on your device. 

Hackers are increasingly using credential stuffing to take advantage of, and misuse compromised usernames and passwords

What separates credential stuffing from brute-force attacks?

Credential stuffing is a specialized form of a brute-force attack that is much more powerful than brute-force attacks in general.

Using the popular username and password combinations, brute-force hackers attempt to guess passwords. As a result, the probability of success decreases.

Hackers who use password stuffing already have valid user information obtained from a data breach.

They often use the stolen credentials to access various other websites, making credential stuffing much more powerful and dangerous than traditional brute-force attacks.

Is Credential Stuffing a Serious Threat?

Many people may not have several email accounts from which to work. As a result, they use the same email address for virtually all of their operations. 

The presumption that many people reuse their passwords through various services is, unfortunately, right.

So, if a hacker has the credentials for one service that subscribes to a user’s unique email address, what is preventing hackers from using those credentials on other services?

This is the fundamental concept of credential stuffing. Of course, that is a cybersecurity threat.

As a result, it is easy to see how a simple act of carelessness on the average user might have far-reaching consequences.

How does it work?

Credential stuffing carries out by using botnets and automated scripts. 

These bots then combine with proxies, which spread botnet attacks across several IP addresses and make them appear reliable.

Hackers first obtain credentials before going on to the next step, including checking those credentials against other resources.

They use bots and automated systems to speed up the process dramatically.

Not only that but by using automation tools, they can broaden the reach of their hacking activities and hack a far greater number of accounts than they could manually.

It’s also possible to hack into other services that don’t use the same login credentials after each successful cross hacking attempt.

This can be accomplished by using password patterns. In this case, the next move is to use brute force algorithms to break specific unknown passwords, getting access to previously unknown credentials as a result.

No company is immune to such attacks, which necessitates careful patching practices and authentication protocols from providers. 

Credential stuffing is more successful on high-traffic websites where an unexpected spike in user logins anticipates.

Detection and prevention of credential stuffing

There are many ways to identify a credential stuffing attack.

  • Trace for a considerable number of login attempts to an account.
  • Monitor access attempts to multiple accounts.
  • Identifying known malicious endpoints trying to use the credential via their IP address or fingerprinting methods.
  • Identifying the usage of automation software in the login process.
  • Trying for passwordless authentication.

How can users protect credential stuffing?

Here are some guidelines for how individual users should protect themselves:

Do not reuse passwords:

Let each of your online accounts have a different password.

That way, even though your password has been stolen, it cannot be used to access other websites.

Attackers will attempt to use your credentials in other login forms, but they will reject.

Password Manager: 

If you have accounts on many websites, recalling solid and unique passwords is virtually impossible, as almost everyone does. 

Use a password manager to trace your passwords. It is even capable of creating robust passwords from scratch.

Two-factor authentication: 

You must have something else each time you log in to a website with two-step authentication, such as a code created by an app or sent to you via SMS. 

Even if an intruder knows your username and password, they won’t access your account unless they have the verification code.

How will organizations protect them against credential stuffing?

Multi-factor authentication: 

Multi-factor authentication is the most effective protection against most password-related attacks, such as password spraying and credential stuffing.

Consequently, it should be used wherever possible, depending on the application’s target audience.

IP Blacklisting:

Since attackers usually have a small pool of IP addresses, blocking or sandboxing IPs that try to log into multiple accounts is another effective defence.

To minimize false positives, you can monitor the last few IPs used to log into a particular account and compare them to the alleged wrong IP.

Flag unrecognized devices: 

A credential stuffing attack is most likely to come from a different, unidentified computer, so keep an eye on the devices trying to access your accounts to help avoid attacks.

Often search IP addresses to see if the computer making the request is one that your team has seen before. 

Companies can use cookies to save accepted logins and verify devices in the future. If the login is coming from an unknown source, additional steps to verify should take the user.


For each login attempt, requiring a user to solve a CAPTCHA will help avoid automatic login attempts, slowing down a credential stuffing or password spraying assault significantly.

CAPTCHAs are not flawless, and some methods can be used to crack them with a high success rate in certain situations.

To increase usability, only requiring the user to solve a CAPTCHA when the login request is deemed suspicious might be desirable.

Align Website Architecture:

If you want to achieve the minor possible attack surface, the best approach is to match the website architecture with various client styles.

To different degrees, several companies have already done so. Others will need to redesign their websites to achieve this.

By having the most granular control of transactional URL traffic, breaking existing endpoints into different URLs reduces the attack surface.


There is no ideal solution for stopping credential stuffing attacks from attackers is a challenge in cybersecurity.

We should make it more difficult for the attackers in the hopes that if we slow them down, they will give up and move on to other goals.

However, the most successful way is to use bot detection and prevention solutions to detect credential stuffing attempts in real-time.

It’s crucial to prevent false positives while detecting and handling bad bots to not inadvertently block legitimate human traffic and successful bots that will help your site.

This is why everybody needs a good bot mitigation solution that can conduct behavioural-based analysis.

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