How to defend against brute force and password spray attacks

From zero-day exploits to polymorphic malware, today’s organizations must protect themselves against increasingly sophisticated cyber threats. But while these types of complex attack vectors may be making the news, the reality is that your organization can’t afford to neglect the persistent threat of brute force attacks.

What brute force methods lack in finesse, they make up for in sheer persistence as they systematically attempt countless combinations to breach defenses. Neglecting to protect against brute force attacks can leave an otherwise well-defended system vulnerable, much like an overlooked weak link in a strong chain. 

In this post, we’ll explore common types of brute force techniques and discuss ways to fortify your defenses against these kinds of attacks. 

What are brute force techniques

At their core, brute force techniques are a methodical approach to compromising access credentials. Hackers use computational power to systematically test massive numbers of password combinations until they identify the correct one.

How effective these attacks are often depending on two things: the strength of the targeted passwords and the defensive measures in place.

Varieties of brute force attacks

• Exhaustive search: This approach tests every possible combination of characters until it finds the correct password.
• Dictionary attacks: Using lists of common passwords and phrases, these attacks exploit the human tendency to choose easily remembered (and guessed) passwords.
• Reverse brute force (Password Spray): Instead of targeting a specific user account, this method tests a single common password (e.g., Password12345) against multiple usernames.
• Hybrid techniques: Combining elements of both exhaustive and dictionary-based approaches, hybrid technique attacks add a level of complexity to hacker’s password-guessing attempts.

The mechanics and vulnerabilities

According to Verizon, 89% of breaches involved the human element, including using stolen credentials or brute force methods. This statistic highlights the importance of robust password policies and user education.

Brute force techniques take advantage of weak password practices and inadequate security protocols.

Their effectiveness stems from several factors, including:

• Computational power: Modern hardware can test millions of combinations per second.
• Password reuse: Many users recycle the same password across multiple accounts.
• Predictable patterns: Attack algorithms can easily factor in common substitutions (e.g., "3" for "E"). End users will often start passwords with a capital letter and end it with a 1 or ! in order to meet complexity requirements. The brute force attack can try these combination types first. 

Real-world impact

The recent Dell cybersecurity breach illustrates the devastating potential of brute force attacks. An attacker reportedly accessed the data of up to 49 million customers by bombarding Dell's partner portal with thousands of requests per minute — for weeks.

This incident highlights the vulnerabilities even in large tech companies, demonstrating how persistent attacks on seemingly low-risk entry points can lead to massive data compromises. 

Fortifying defenses against brute force attacks

A multi-layered defense strategy is your best bet for mitigating the impact of brute force techniques. Key components of your strategy should include:

Enforce robust password policies

Ensure passwords are at least 15 characters, incorporating a mix of uppercase and lowercase letters, numbers, and special characters. Encouraging end users to create memorable passphrases is the best way to get strong and user-friendly passwords.

Implement multi-factor authentication (MFA)

MFA adds a layer of security by requiring additional verification beyond the password. And it works — a study by Microsoft found that MFA can block 99.9% of automated attacks, making it a valuable tool in your cybersecurity arsenal.

Monitor and limit login attempts

• Automated lockouts: Don’t make it easy for hackers to keep trying. Configure systems to temporarily lock accounts after a specific number of failed login attempts.
• Progressive delays: To slow down automated attacks increase wait times between failed login attempts.

Perform regular security audits

Conduct periodic assessments of password strength across your organization. Take advantage of free tools — like Specops Password Auditor — to gain valuable insights into your password ecosystem’s potential vulnerabilities. Download your free tool here and run a read-only audit of your Active Directory.

Provide end user education

Develop comprehensive training programs to educate end users about the importance of strong passwords and the risks associated with poor password hygiene. Emphasize that every individual — from the CEO to the customer service agent — plays an important role in maintaining organizational security.

Advanced tools for enhanced protection

While foundational security practices are essential, you can further strengthen your defenses against brute force attacks by investing in specialized tools. For example, Specops Password Policy offers a comprehensive suite of features that addresses the complexities of modern password security, including:

• Customizable password rules: Tailor password requirements to meet your organization's specific needs while ensuring you comply with industry standards.
• Real-time password monitoring: Continuously check passwords against a database of over 4 billion known compromised credentials, including those actively being used in attacks.
• User-friendly interface: Guide employees on creating strong, policy-compliant passwords without sacrificing usability.

By implementing these advanced features, you can dramatically reduce your organization’s vulnerability to brute force attacks while maintaining a positive end user experience.

Try Specops Password Policy for free today.

Don’t underestimate the power of brute force attacks

At a time when digital assets are increasingly targeted by sophisticated cyber threats, don’t discount the risk of brute force attacks. By implementing robust password policies, leveraging multi-factor authentication, and utilizing advanced security tools, you can boost your organization’s resilience against these persistent attacks.

Want to learn more about defending your organization from brute force techniques? Speak to a Specops expert.

Sponsored and written by Specops Software.