Effective Strategies to Prevent Password Spraying in Email Security

Keeping passwords safe may be an obvious necessity. What about the usernames your team uses to access your system?

That’s right. Password spraying is a hacking technique that mainly depends on having authentic usernames. In many cases, if cyber criminals know someone’s actual name, they can often guess the username.

In this guide, we’ll explain how to protect your email accounts from password-spraying attacks.

What Are Password Spraying Attacks?

Password-spraying attackers use the same password to break into multiple user accounts. These hackers pose a cyber threat through brute force. Their methods are often less sophisticated than, say, email viruses.  

However, spraying is a different approach than typical password hacking. Hackers use common or popular passwords and try them on every available username on a platform, such as an email server.

Password spraying enables cybercriminals to evade certain detection methods. They don’t focus on a single account. By spreading their efforts, they are less likely to alert intrusion systems.

Brute Force vs Password Spraying vs Credential Stuffing

In a typical brute-force attack, someone attempts every common password or combination to gain access to a single user account. This traditional brute-force method is also known as a password-guessing attack. 

In contrast, password spraying is essentially the inverse process. A criminal tests multiple accounts with one key.  

Credential stuffing is a different technique altogether. Hackers gain real login credentials from stolen or leaked password lists. Compromised accounts may have been secured. However, many people use the same username and password for multiple accounts. Hackers can try the same combinations on other popular platforms.

How Password Spraying Works

Okay, password spraying sounds simple enough, right? To better mitigate hackers, it helps to first understand their process.

1. Get a List of Usernames

Everything starts with having a list of the users who access your email portal. Scammers can gain these through various means, such as phishing and social engineering. Alternatively, merely having a list of employees can be good enough to guess usernames. 

2. Password Selection

Next up, they go over updated lists of popular passwords such as “password” or “123456.” What they decide to use may depend on current trends, seasonal events, or what industry they operate in.

3. Spray Passwords

Once they have their weapon of choice, hackers begin spraying credentials and hoping something sticks. They typically only try one password per account. If the attempt fails, they move on to another, preventing locked accounts from flagging your security measures.

4. Gain Access and Spread Attack

Once a malicious actor gains access to an email account, the world is their oyster. They can attempt to increase account privileges or access sensitive data. Resourceful trespassers can even create new ways for them to access your system later on down the line.

Why Securing Your Email Matters

Emails contain plenty of sensitive information about your business and its customers. Marketing strategy, pricing, and financial account details are only a small sample of what cybercriminals can glean from employee emails.
Let’s look at why it’s important to keep your email system secure.

Mitigate Data Breaches

Once someone forces their way into an email account, they can procure credentials to other systems. Now, let’s say they gain access to something like your customer relationship management (CRM) platform and steal data. 

Guess what? The average cost of a data breach was $9.34 million in 2024. 

Protect Reputation

Fines and penalties from legal recourse are one way to hurt your bottom line. However, data breaches and account compromises also spread like wildfire on social media and news sites. Your brand image is tarnished, and you lose consumer trust. Customers flock to competitors, and prospects look elsewhere.

Maintain Compliance

Regulations such as HIPAA and the European Union’s GDPR require you to meet rigid standards. Securing your email accounts ensures that you safely handle customer information. You'll stay compliant with data privacy and protection laws.

Financial Health

Let’s get this straight: compliance fees, reputational damage, and a loss of customers? Are you getting all of this? Failing to secure company email from spraying attacks hits your financials in a multi-pronged attack. 

How to Secure Your Business

Email is as old as the internet. However, it’s still a proven method for communicating internally and connecting with customers. 

As technology advances, so do cyber attacks, which is why most businesses are willing to invest in email security. Statista projects the global cloud-based email security market to reach nearly $1.4 billion in 2028.

But before you expand your cybersecurity budget, use these tactics to prevent password spraying: 

Strong Password Policies

A strong password policy is your first line of defense against hackers. It takes very little effort to generate passwords that are nearly impossible to guess. With complex combinations, frustrated cybercriminals will move on to their next potential victim.

Enforce strong password policies that include:

• Passwords must be at least 12 characters in length
• Words and phrases must be a combination of numbers, letters, and special characters
• Frequently change passwords
• Never repeat the same password
• Remove credentials for exiting employees right away
• No common or easily guessed passwords (make a list)

Create a document with the above points for employee reference and security onboarding purposes.

Multifactor Authentication

Multifactor authentication (MFA) is a simple way to reinforce your account security. MFA requires users to provide two different forms of account verification. The login credentials are one. Separately, they use a supporting method such as email, text message, or WhatsApp verification. More advanced authentication methods include biometrics such as fingerprints or facial recognition.

If a cybercriminal matches credentials, they will be stopped dead in their tracks by MFA. The only workaround is to have access to a second account or device for the same user. 

Employees who are sent unsolicited verifications are made aware of a possible attempt. An unexpected MFA request may also signal it’s time to change their password. 

Monitor and Detect Threats

Monitor your email applications for login attempts and threat detection. Some useful tools to automate this process include Security Information and Event Management (SIEM) platforms and Intrusion Detection/Prevention Systems (IDPS). 

These apps monitor every login attempt. Security tools alert you when failed login attempts spread rapidly across multiple accounts. Solutions that use Agentic AI may be able to identify threats, lock accounts, and send password reset emails without involving any team members. 

You can also track user behavior with AI-powered email security. Algorithms detect irregularities such as unusual login times or suspicious IP addresses. Identify threats as soon as they enter your radar. Your IT security team can quickly neutralize threats and recure breached accounts. 

Educate Team 

One of the best ways to combat cyber attacks like password spraying is through education. Train your team to identify suspicious login attempts, such as when receiving an MFA code on their smartphone.

Part of the onboarding process involves creating email credentials for new employees. Use your strong password policy document to guide employees. Implement a company-approved password manager tool. These apps help team members generate and recall robust, complex passwords for multiple accounts.

It’s crucial that employees also understand and can identify threats like email phishing. Such knowledge helps them stay proactive with account security.

Lock Affected Accounts

So, what happens when an account is compromised? Well, the first step is that someone needs to identify and report a successful or attempted breach. Establish clear reporting procedures for suspected account hacks. 

Your IT teams will take it from there and inspect the account, locking it if compromised. The team will also guide employees through the password reset process. They can also take this opportunity to re-emphasize your strong password practices.

While not strictly for password spraying attacks, it’s useful to lock accounts after a certain number of failed login attempts. Use rate limiting to block IPs and even temporarily pause the system when a spray attack is caught in the act. (You can do this automatically with the intrusion detection tools mentioned previously.)

Conduct Regular Audits

One of the best ways to secure any part of your business is to conduct regular audits and reviews. Thorough examinations identify weaknesses and spot potential vulnerabilities. Audits also keep everyone on their toes.

Conduct email security audits that include:

• Simulated social engineering and phishing attacks
• Email authentication protocols such as Sender Policy Framework (SPF)
• Access control and password policy assessment
• Evaluate protection layers such as TLS/SSL email encryption
• Audit email gateway security like anti-spam filters and malware detection
• Assess compliance requirements
• Examine all onboarding and email security documentation
• Ensure all hardware and software is up to date, including BYOD smartphones and desktops.

Implement Identity and Access Control

Use an identity and access management (IAM) framework so that the right people have access to the right resources. In other words, you need a system in place to ensure that no one is mistakenly given extraneous privileges and permissions. For instance, you probably don’t want a trainee employee to have login credentials for a vital ERP system integration. 

A strong password policy and multifactor authentication are key components of any IAM.

Other identity and access control measures include:

• Controlled resource provisioning- better manage access to sensitive data and systems.
• Role-based access control- permissions tied to specific job roles. For example, an administrator may have permission to create new email accounts.
• Rate limits- prevent a large number of login attempts from a single IP address.
• User access controls- central space to limit data and system access for users.
• Advanced analytics- machine learning (ML) algorithms to analyze login behavior across multiple platforms.

Collaborate with Security Leaders, Stay Updated

Collaborate with security experts and industry peers. Share best practices and stay informed about emerging threats. Join a threat intelligence platform like CrowdStrike or IBM X-Force Exchange. These networks provide space to standardize and streamline the sharing of cybersecurity knowledge.

Subscribe to security advisories and threat intelligence feeds. They will send you regular updates on vulnerabilities and attack trends. You'll stay on top of password spraying and other threats. Keeping in the know pushes your security ahead of the curve and minimizes risk.

Protect Your Business from Password Spraying Attacks

Password spraying is a low-effort, high-reward tactic for cybercriminals. All it takes is a list of usernames and a handful of common passwords to put your business at risk.

Don’t let that happen.

Start with the basics: enforce strong passwords, require MFA, and monitor for unusual login behavior. Back it up with employee training, regular audits, and clear security protocols.

This isn’t just about keeping inboxes safe — it’s about protecting your data, your customers, and your company’s future.