Hackers are stepping up their game—again.

On April 29, 2025, Microsoft confirmed a widespread password spraying attack carried out by a hacking group known as Storm-1977. 

The campaign specifically targeted cloud tenants in the education sector, using stolen credentials and automation tools to break into containerized environments and launch cryptomining operations.

This blog breaks down what happened, how these attacks work, and what your business can do to stay safe.

What Is a Password Spray Attack?

A password spray attack is a type of brute force attack where hackers try the same password across many usernames.

Unlike traditional brute force methods that target a single account with multiple guesses (and risk account lockout), this approach helps attackers fly under the radar by spreading login attempts across many users.

Here’s why it’s dangerous:

• Many users reuse simple passwords like Welcome123 or Password1.
• Attackers often use breached password lists easily found online.
• It’s hard to detect without advanced monitoring tools.

In short: if just one weak account exists in your environment, hackers can gain a foothold.

What Happened in the Storm-1977 Attack?

According to Microsoft’s Threat Intelligence team, Storm-1977 used a command-line tool called AzureChecker to download encrypted target lists for their attack. 

They combined this with known username/password combos and tested them across multiple cloud environments.

Once they got in, the group:

• Used guest accounts to build a fake resource group
• Spun up over 200 containers for cryptomining
• Exploited inactive and unsecured workload identities

It’s a classic example of how attackers use valid credentials to move laterally and stay hidden longer.

How to Protect Against Password Spraying Attacks

You can’t stop every threat—but you can reduce your exposure. Here’s what Constructure Technologies recommends:

1. Go Passwordless Where You Can

Eliminate passwords in favor of passkeys, biometrics, or secure tokens. These methods are harder to steal or guess.

2. Enforce Multi-Factor Authentication (MFA)

MFA adds a second layer of security, which blocks most automated attacks—even if a password is correct.

3. Lock Down Cloud Identities

Review workload identities and remove or rotate any that are inactive or unused. Use role-based access controls (RBAC) to limit permissions.

4. Monitor for Unusual Activity

Set up alerts for failed login attempts, guest account usage, and unusual cloud resource creation.

5. Use Tools That Detect Password Spray Attempts

Advanced threat detection solutions—like Microsoft Defender for Cloud—can help you spot and respond to these attacks early.

Conclusion: Stay Secure with Smarter Cyber Defense

The Microsoft password spraying attack is a clear reminder: even one weak login can open the door to major damage. As threats evolve, so should your defenses.

Here’s what you need to remember:

• Password spray attacks target multiple accounts with common passwords to avoid detection.
• The Storm-1977 group exploited inactive identities and cloud misconfigurations to deploy cryptomining containers.
• The best defense includes multi-factor authentication, passwordless solutions, and active monitoring.

Constructure Technologies delivers smarter, custom-fit protection for businesses of all sizes. Our cybersecurity solutions help you stay ahead of threats with:

• 24/7 network and email security monitoring
• Penetration testing and vulnerability assessments
• Compliance support and continuous risk management

Call 631.396.7777 to protect your business from the next breach.

Let Constructure Technologies be your cybersecurity partner—so you can focus on running your business while we focus on defending it.