Credential stuffing attacks - a category of cyberattack where stolen usernames and passwords are used to gain unauthorized access to websites -  are a SUBSET of brute force attacks. Brute force attacks are a classification of attacks that aim to exploit systemic vulnerabilities for financial, informational, and strategic gains, with little to no context. 

Credential stuffing uses exposed data in its efforts, while brute force uses common passwords and random attempts to exploit  -  brute force is more of a hammer approach, while credential stuffing is more surgical (targeted and strategic in nature). 

Credential Stuffing

What are credential stuffing attacks?

Credential stuffing is a type of cyberattack where stolen usernames and passwords are used to gain unauthorized access to multiple websites, exploiting the common practice of password reuse to carry out fraudulent activities. Think about your own passwords - you very likely have a small number or even one core password with slight variations; this is exactly why credential stuffing attacks are successful. 

How does credential stuffing work?

To carry out a credential stuffing cyberattack, hackers use stolen login credentials to attempt access to different sites, employing tools like botnets and IP rotation to avoid detection. Once logged in, attackers can initiate an account takeover, turning a single stolen credential into a much larger threat.

Here’s what a credential stuffing attack looks like: 

• Initial data aggregation: Hackers gather lists of usernames and passwords stolen in data breaches or buy them from criminal sites on the dark web. Stolen password lists can contain hundreds of millions of usernames and passwords, and are often available to bad actors for a relatively small sum.

• Credential validation infrastructure:: At this stage, the cybercriminals use special computer programs called bots to try logging into many websites simultaneously. These automated programs can test thousands of passwords every minute. To make attacks more effective, fraudsters can instruct multiple compromised computers to work together in a botnet.

• Proxy and IP rotation mechanisms: Attackers use special tools to hide where the attacks come from by changing network addresses. Multiple fake locations help mask the real source of the attack even more effectively and avoid getting caught by security systems.

• Advanced bot technologies: AI bots are new hacking tools that are very good at imitating real people online. These programs even add random delays and mouse movements to fool security systems. 

• Geographical distribution strategies: Hackers launch attacks from different countries worldwide to prevent suspicion. Login attempts come from places like Europe, Asia, and America simultaneously. Spreading attacks across the globe makes them harder to stop.

• Protocol exploitation: Attackers look for weak spots in how websites handle logins and passwords. Problems with password reset options give hackers more ways to break in. Old or poorly set up security makes a successful attack more likely.

How can you prevent credential stuffing attacks? 

Preventing credential stuffing attacks requires a multi-pronged security strategy. Best practices include the following: 

1. Advanced multifactor authentication. Adding a second login step, like an OTP code sent to a phone, can block unauthorized access even when a bad actor has obtained a stolen password. 

2. Behavioral biometric integration. Context-aware authentication software can further enhance protection by analyzing user behavior and interaction patterns, such as how users swipe screens or type. Checking these unique patterns blocks fake logins, even with the right password. 

3. Zero-trust architecture implementation. Implement security systems that require users to prove their identity with every login attempt. Assuming no inherent trust stops breaches before they start, ensuring that only verified users can access sensitive data.  

4. Adaptive rate limiting. Use intelligent software that detects too-rapid login attempts from bot networks. Slowing down logins when this happens allows time to investigate and stop attacks. This sort of rate limiting keeps out credential stuffing bots but doesn't interfere with real users.  

5. Advanced bot detection technologies. Deploy machine learning tools to differentiate between human logins and automated bot activity patterns. Blocking simulated logins helps prevent large-scale stuffing campaigns from even getting started. 

6. Passwordless authentication strategies. Adopt passwordless authentication methods like WebAuthn that rely on cryptographic keys tied to specific devices. These strategies eliminate the risks associated with traditional passwords, rendering stolen credentials useless. 

7. Automated credential rotation. Ensure login credentials are regularly updated by using automated systems that force resets when potential compromises are detected. This prevents attackers from reusing passwords and reduces the risk of breaches caused by human error.   

8. Threat intelligence integration. Staying updated on emerging exploits ensures your security continues to be effective in the face of new threats. Key resources include CERT/CC, SecurityFocus, and the National Vulnerability Database, which provide searchable and sortable information. For in-depth security news and threat intelligence, follow sources like SANS Internet Storm Center, CERT-EU.

9. Honeypot and deception technology. Set up decoy systems to divert attackers from real assets. Honeypots not only protect your systems, they also help you refine your security strategies by gathering valuable data on hacking techniques.

10. Continuous penetration testing. Engage ethical hackers to carry out regular penetration testing to thoroughly test your system's defenses. They can identify and analyze vulnerabilities and offer advice on how to strengthen your security measures.

Brute Force Attacks

What is a brute force attack?

A brute force attack is a cyberattack where a hacker uses software to systematically test different password combinations to gain access to an account without authorization.

It's called "brute force" because attackers rely on computing power to repeatedly guess passwords, rather than using advanced techniques or skills. 

What are brute force attacks used for?

Brute force attacks are aimed at exploiting systemic vulnerabilities for financial, informational, and strategic gains. According to Google, this approach remains the most commonly used method for targeting cloud platforms. For example, an AhnLab Security Emergency Response Center (ASEC) study shows that brute-force attacks target servers, using botnets and malware like Mirai and P2Pinfect to breach systems. 

What are the different types of brute force attacks?

There are several different types of brute force attacks, one of which is credential stuffing:

• Credential stuffing: Hackers exploit large lists of stolen usernames, emails, and passwords obtained from past data breaches - a common tactic known as credential stuffing. 

• Dictionary attacks: Cybercriminals often use software that can try endless combinations of common dictionary words in multiple languages to crack passwords.

• Hybrid attacks: These are sophisticated methods that combine different types. For instance, hackers can combine a dictionary attack blueprint with numerical and special character permutations along with real leaked passwords for higher accuracy.

• Rainbow table attacks: Here, attackers use pre-computed password hashes to accelerate password discovery processes. They check breached database copies against your system for matches to unlock access, making attacks faster and more challenging to trace.

• Mask attacks: These types of attack focus on exploiting known password structure patterns and complexity requirements alongside partial information. For instance, if the first few strings of a password are known, hackers use algorithms to predict the remaining characters.

• Distributed attacks: Large computational nodes coordinate across thousands of devices to boost brute force capacity and speed.

How to prevent credential stuffing and brute force attacks

How to prevent brute force attacks 

Preventing brute force attacks requires establishing multilayered defensive systems to detect and stop unauthorized access attempts. Remember that credential stuffing attacks ARE a type of brute force attack, so these strategies will apply to both. 

The following best practices can help to minimize the risk of a brute force attack:

1.  Implement advanced authentication protocols. Upgrade from basic passwords to multifactor authentication with adaptive risk assessment capabilities. This approach requires your customers and employees to validate by completing additional steps like entering one-time codes sent to phones or biometric authentication. Extra measures like these significantly raise the difficulty of brute-forcing into accounts.

2.  Develop intelligent password policies. Enforce strong password protocols that combine greater complexity requirements with password expiration and rotation policies. Use centralized identity management platforms to blacklist commonly attacked passwords and set minimum standards for length and character types. Apply AI-driven tools to identify and address weak or reused passwords.

3.  Design sophisticated rate-limiting mechanisms. Create access controls to block repeated failed login attempts from the same IP address or range. This protects against sustained attempts to guess passwords while maintaining accessibility for legitimate users. Ensure proper configuration to avoid unintentionally locking out valid accounts.

4.  Integrate real-time threat intelligence. Connect security infrastructure with global threat monitoring platforms to stay up to date on malicious IP addresses, compromised credentials, and attack techniques. Also, automate analytics systems to monitor networks and accounts for early brute force indicators.

5.  Optimize network segmentation. Strategically compartmentalize systems and data access to limit damage if credentials are compromised. Restrict VPN and external entry points while granting employees minimal access levels. If you serve customers in a specific location, you can use geo-blocking to prevent attackers from other countries accessing your sites or apps.

6.  Conduct regular penetration testing. Provide ethical hackers with authorization to attempt to breach your defenses using simulations of brute force attacks and other cyber threats. Pentesting like this uncovers vulnerabilities and allows you to continuously strengthen your cybersecurity.

7.  Invest in behavioral analytics. Profile typical user patterns around data access, applications, and geographic movements. Machine learning algorithms can automatically 

detect anomalous behaviors indicative of credential misuse and preemptively terminate suspicious sessions.

How can Fastly help prevent brute force attacks?

Fastly delivers strong protection against brute force attacks with an integrated security tool suite designed to rapidly deploy layered defenses across your website and apps. 

Next-Gen Web Application Firewall (WAF): Fastly's Next-Gen WAF monitors and filters incoming web traffic,automatically blocking suspicious activity associated with brute force attempts. It provides instantaneous visibility into emerging threats.

DDoS protection: The solution shields against distributed brute force attempts by absorbing and filtering malicious traffic before it reaches your servers.

Rate limiting: This feature rapidly restricts the requests a single customer or IP address can send within a set timeframe, helping prevent automated brute-force attempts.

Edge security: The platform deploys defenses closer to the source of the attack, minimizing latency while effectively blocking threats.

TLS/HTTPS enforcement: Fastly ensures encrypted communication channels, protecting against interception and credential sniffing during brute force attempts.

Fastly offers a bot management service designed to detect and block harmful bot traffic used in cyberattacks like credential stuffing. 

• Automatic bot detection: Fastly quickly distinguishes real users from bots. Before blocking, the system double-checks to avoid mistakes that may frustrate genuine users.  

• Real-time threat classification: Because Fastly identifies threats right when they happen, you can act immediately to stop attacks. 

If you’re interested in more information on how Fastly can secure you against brute force and credential stuffing attacks, you can get in touch