Microsoft Explained: How Phishers Use Email Misconfigurations to Bypass Security

Microsoft states that hackers are now adopting a new tactic. They exploit the complex routing mechanisms within a company’s email system. In areas where spoof protection is weak, they easily dispatch fake emails that appear indistinguishable from genuine internal company correspondence. Simply put, the email looks authentic, but in reality, it originates from a hacker; it is fake.

What has Microsoft said about this phishing attack?

According to Microsoft, a new phishing trend is growing quickly. In this attack, hackers try to trick people by making fake emails look like real company emails.

1. Using the complexity of the email system
   Company email systems are complicated. Hackers use this complexity to send fake emails through the system so they look more legitimate.
2. Taking advantage of weak email security settings
   Some companies do not set up email security protections correctly. Hackers use these weak settings to send spoofed or fake emails.
3. Making fake emails look like internal emails
   Hackers create emails that appear to come from someone inside the company, like a manager, HR team, or IT department. 

How do these attacks work?

Hackers are no longer using only simple phishing emails. They are now using smarter methods to make their attacks look real.

1. Fake internal identity emails
Hackers send emails that really look like they’re coming from inside your company. Maybe it’s a message from “HR,” an IT security alert, a salary update, or a password reset request. Since these messages look so official, people just assume they’re real, and that’s exactly what the attackers want.

2. Email routing loopholes
If your company’s email system isn’t set up just right (things like incorrect MX records), nasty things start to happen. Email verification can get mixed up, and fake or spoofed emails can sneak past your usual security checks. Hackers love this kind of chaos.

3. Phishing-as-a-Service tools
These days, attackers don’t even need to be tech geniuses. They can just buy or rent phishing kits and services, like Tycoon2FA. These kits offer fake login pages, pre-made templates for phishing emails, and even the hosting infrastructure hackers need. This makes running a phishing campaign pretty much plug-and-play.

4. Spoofed domain misuse
Hackers are also good at sending emails that look like they’re from your own company’s domain. The “From” address looks completely legit, so the message seems to come straight from your internal system. Unsuspecting employees trust these messages and do what the email asks—never realizing they’re being duped.

What makes this attack dangerous?

If an email looks like it came from inside your company, maybe from HR, IT, or your manager, and comes off as urgent, most people drop their guard. They react quickly. They don’t pause to double-check.

That’s when things go sideways. Employees end up entering their login info or clicking a link, thinking everything’s legit.

This can lead to serious problems such as:

• Credential theft – hackers steal the employee’s username and password
• Account takeover – attackers gain control of the employee’s account
• Business Email Compromise (BEC) – hackers use the account to send fake emails inside the company
• Financial fraud – attackers may trick the company into sending money or sensitive information

What has Microsoft observed?

Microsoft has noted that such attacks have surged significantly since 2025. Microsoft Defender has blocked millions of phishing emails to date. Attackers are now targeting random companies and industries. 

What is the most effective way to stay safe?

The most effective way to stay protected is to strengthen your email system while simultaneously keeping your users informed.

How does Ransom Security help you?

Ransom Security is a ransomware protection service provider that secures businesses not just after an attack, but before one even occurs.

We fix email security

• We strengthen configurations such as SPF, DKIM, and DMARC to close off phishing entry points.
• We block fake internal emails.
• We stop spoofed and suspicious emails before they ever reach the inbox.
• We detect advanced phishing attempts.
• We identify and block even modern phishing attacks, such as Tycoon2FA.
• We secure email routing.
• We fix complex routing configurations and risky connectors to ensure the system remains clean and safe.

Backup & Recovery (The Real Protection Layer)

• Immutable Backup & Cloud Backup: We maintain secure backups that attackers cannot modify or delete.
• Pre-Attack Protection Approach: We secure the system proactively to ensure that attacks cannot succeed.
• Security Restoration Service: Even if data is compromised, we facilitate rapid recovery and system restoration to quickly return the business to its normal operational state.