Password Spraying Attacks: What They Are and How to Stop Them 

It’s no secret that passwords are very often the weakest link in an organization’s network because users still frequently neglect basic cybersecurity best practices. Aware of the poor state of password security, cybercriminals are constantly coming up with new ways to exploit it, and password spraying has emerged as a particularly effective technique in their arsenal. 

What Are Password Spraying Attacks? 

Password spraying attacks exploit the unfortunate reality that many people choose simple, predictable passwords (like “password123” or “qwerty”). Attackers know this, and they leverage it in three simple steps:  

1. Attackers start by gathering a large list of usernames. These can be obtained through data breaches, social engineering, or even scraping company websites. 

2. Using automated tools, they systematically attempt to log in to many accounts using one common password. 

3. They repeat this process with different common passwords. Because they’re only trying a few passwords per account, they often fly under the radar of typical security measures. 

Despite its seemingly simplistic nature, password spraying is not to be underestimated, as pointed out by the US Cybersecurity & Infrastructure Security Agency (CISA) in one of its cybersecurity advisories.  

The real danger of password spraying lies in its reach. Attackers can target hundreds or even thousands and, in the case of attacks on public-facing cloud services, even millions of users at once, so the chance of at least one or two accounts using a common, weak password is relatively high.  

It then doesn’t take more than a single account to provide a foothold into the broader network, leading to potential data breaches, ransomware attacks, or further exploitation of system vulnerabilities. 

Password Spraying Attacks Vs. Brute-Force Attacks 

While both password spraying attacks and traditional brute-force attacks aim to gain unauthorized access to accounts, each approaches the objective differently:  

• Brute-force attacks: Focus on a single account by relentlessly trying many different password combinations in rapid succession to break in. This often triggers account lockouts. 
• Password spraying attacks: Target many accounts simultaneously, trying only a few common passwords per account. This “low and slow” approach is designed to avoid setting off alarm bells. 

Basically, a cybercriminal performing a password spraying attack is like a car thief who walks through a parking lot, pulling on each car’s door handle just once to find any cars left unlocked for easy access. This method is less likely to attract immediate attention compared to breaking into a single car with force or multiple tools.  

Password Spraying Vs. Credential Stuffing 

Though both password spraying and credential stuffing are tactics used by cybercriminals to breach accounts by automatically injecting passwords, there’s one critical difference between them. 

Cybercriminals who perform credential stuffing attacks use already compromised usernames and passwords (from previous data breaches), hoping that people reuse the same login credentials across different platforms. On the other hand, password spraying attacks use common passwords, such as those found on various lists of the most common passwords of the year. 

How to Defend Against Password Spraying Attacks  

Despite the stealth and efficiency of password spraying attacks, there are robust defenses that organizations, including small and medium-sized organizations, can deploy to safeguard their digital environment: 

• Enforce strong password policies: Mandate complex passwords that mix letters, numbers, and symbols. Disallow common words or easily guessable patterns (like birthdays). Educating employees on the importance of unique passwords for different accounts can also diminish the risk. 
• Non-standard usernames: Using non-obvious usernames can make it harder for attackers to even start the password spraying process because it adds an additional layer of complexity to the guessing game. Examples of non-obvious usernames include mixing letters with numbers, using middle names or initials in unexpected ways, or incorporating special characters.  
• Use Multi-Factor Authentication (MFA): Require an additional verification step, like a code sent to a smartphone app, a biometric scan, or a physical security key. This makes it exponentially harder for an attacker to succeed, even if they have the correct password.  
• Implement rate-limiting: Configure systems to limit login attempts from a single IP address within a certain period. This slows down automated attacks and increases the chance of detection before attackers have a chance to breach your network. 
• Adopt a Zero Trust approach: Implementing a zero trust security approach, where no user or device is trusted by default from inside or outside the network, can significantly enhance your defense against password spraying. This approach minimizes the attack surface by limiting access to resources to only what is needed, based on the user’s role and context. 
• Watch for Signs of Password Spraying: Regularly monitor your logs for these red flags: 

• Spikes in failed login attempts across many accounts 
• Login attempts from unknown locations or devices 
• Login attempts for inactive or non-existent user accounts 

Our cybersecurity experts can assess your current security posture, design a tailored defense plan, implement the above-described safeguards, and proactively monitor your systems for any signs of password spraying attempts. 

Don’t let weak passwords be your Achilles heel. Schedule a meeting with OSIbeyond today to fortify your defenses! 

Conclusion  

Password spraying attacks are a growing threat, and their simple-yet-effective nature makes them surprisingly effective against organizations that are not prepared. However, the good news is that implementing proven defenses can dramatically lower your organization’s risk.