A massive cyberattack is underway, with a botnet of over 130,000 compromised devices targeting Microsoft 365 accounts. Hackers are using password spraying techniques to break into accounts and exploit outdated security protocols. Here’s everything you need to know and how to stay protected.
What’s Happening?
A newly discovered botnet, suspected to be linked to China-based cybercriminals, is actively attacking Microsoft 365 (M365) accounts. The attack leverages a technique called password spraying, where hackers try a small set of commonly used passwords across multiple accounts instead of brute-forcing a single one. This method helps them avoid triggering security alerts and account lockouts.
What makes this attack particularly dangerous is that it exploits non-interactive sign-ins using Basic Authentication—a legacy protocol that lacks strong security measures. Many businesses still rely on outdated authentication methods, making them an easy target for cybercriminals.
How Does the Attack Work?
Massive Network of Compromised Devices
The botnet consists of 130,000 hacked devices, all working together to carry out automated attacks. These devices, spread across different regions, attempt to log into Microsoft 365 accounts using commonly used passwords.
Exploiting Basic Authentication
Instead of attacking accounts directly, hackers target non-interactive sign-ins, which occur when an application or system automatically logs in without requiring a user to enter credentials. This process often bypasses Multi-Factor Authentication (MFA), making it easier for attackers to gain access.
Password Spraying Attack
Unlike brute-force attacks that try thousands of passwords on a single account (which quickly get detected and blocked), password spraying takes a different approach. Hackers test a small number of weak passwords (like “123456,” “password,” or “admin123”) across many accounts at once.
This method avoids triggering security mechanisms that detect multiple failed login attempts on the same account. If even one employee is using a weak password, the hackers could gain access to their M365 account.
Why Is This Attack So Dangerous?
- It Targets Businesses of All Sizes: Whether you’re a startup or a large corporation, if you use Microsoft 365 with weak authentication settings, you’re at risk.
- It Bypasses Traditional Security Measures: Many organizations assume MFA will protect them, but this attack exploits older login methods that don’t require additional verification.
- It Uses a Massive Network of Hacked Devices: The sheer scale of 130,000 devices attacking accounts worldwide makes it one of the biggest botnet-driven cyberattacks in recent years.
How to Protect Your Business from This Attack
Disable Basic Authentication Immediately
Microsoft has deprecated Basic Authentication, yet many companies haven’t switched to modern authentication methods. If your business still relies on Basic Authentication, disable it now and move to OAuth 2.0, which provides better security.
Enforce Multi-Factor Authentication (MFA)
MFA is still one of the most effective security measures. Ensure that every account requires MFA for login. Even if hackers steal a password, they won’t be able to log in without the second verification step.
Implement Strong Password Policies
Require employees to use long, complex passwords instead of weak, commonly used ones. Encourage passphrases (e.g., “SecureYourData#2024!”) instead of simple passwords.
Monitor Non-Interactive Sign-Ins
Since this attack exploits non-interactive logins, review sign-in logs regularly for any suspicious activity. If you notice unauthorized access attempts, block those IPs immediately.
Regularly Update Security Patches
Ensure that all Microsoft 365 security patches and updates are applied as soon as they are released. Cybercriminals often exploit outdated systems.
Educate Your Employees
Train your staff on cybersecurity best practices. Many cyberattacks succeed because of human error, such as using weak passwords or falling for phishing scams.
The 130,000-device botnet attack on Microsoft 365 accounts is a wake-up call for businesses worldwide. Hackers are constantly evolving their methods, and outdated authentication protocols are a major security risk.
By disabling Basic Authentication, enforcing MFA, and strengthening security policies, you can protect your business from this large-scale attack. Cybersecurity is not just an IT issue—it’s a business survival strategy in today’s digital age.
Don’t wait until it’s too late. Strengthen your defenses now!