Beware the Fake “Messages Blocked” Email Phishing Attack

The “Messages Blocked” email scam is a phishing attack designed to steal personal information and compromise user accounts. This article will provide an in-depth overview of how this scam works, who is behind it, and most importantly, how you can protect yourself.

Scam Overview

The “Messages Blocked” phishing email claims your inbox is full and you have messages that failed to send to multiple recipients. It includes a link to “fix the problem” along with a note to “verify you are not a robot.”

This email is carefully crafted to appear legitimate. The subject line and message content are designed to panic recipients into clicking the link to avoid “blocked messages.”

However, the email address it comes from is not a real system administrator. The link also does not lead to a mailbox storage page. Instead, it goes to a fake login page controlled by scammers.

Once you enter your email login credentials, cybercriminals can access your inbox, contacts, and account settings. They use this to steal personal information or launch additional attacks.

This scam has skyrocketed in popularity since 2021, with millions of these emails sent daily. Their surge in volume corresponds with the rise in remote work and reliance on email for business communication.

Who is Being Targeted?

The scam targets business email users across all industries and regions. However, Trickbot seems particularly focused on larger organizations in English-speaking countries like the United States, Canada, Australia, and the United Kingdom.

Employees at any level may receive the phishing email, as cybercriminals use brute force techniques to send mass volumes. C-suite executives and people in finance roles are high-value targets.

Most reports indicate the scam links go to fake Office 365 login pages. This shows Trickbot’s efforts to infiltrate Microsoft accounts for access to sensitive data.

Potential Damages

If you enter credentials into a fake login page, consider your account fully compromised. Criminals can leverage it to:

• Access your inbox to send more phishing scams using your identity
• Download contacts to target your clients or colleagues
• Adjust account settings like forwarding rules or login requirements
• Access proprietary data, financial records, trade secrets, or personal information
• Install malware like info-stealing Trojans or ransomware

These damages can result in massive financial losses, legal liabilities, and brand reputation harm.

Phishing scams also weaken security cultures by training employees to blindly click links. Ongoing education is essential to avoid real threats exploiting these learned behaviors.

Email Header Analysis

Analyzing email headers reveals signs a “Messages Blocked” email is fake, including:

• Mismatched sender and reply addresses
• Random garbled strings in place of a sender name
• Irrelevant subject lines on enclosed messages
• Differences in encoded and displayed sender names
• Suspicious origin servers from non-corporate IP ranges

Relying solely on header analysis has limitations, however, as scammers constantly test new techniques to mimic legitimate emails. Do not ignore your intuition if an email just seems “off” in some way.

How the Scam Works

The “Messages Blocked” scam uses psychological tricks and technical deceit to steal credentials. Here is a step-by-step overview of how it unfolds:

1. You Receive the Phishing Email

The scam email lands in your inbox and can easily blend in with other messages.

On first glance, it appears to come from your email provider or company IT department. The subject line is urgent, implying a risk of losing message data.

![Messages blocked email screenshot][]

Deceptive “Messages Blocked” Email

2. You Click the Link

Concerned about a blocked inbox, you click the link without much thought. After all, avoiding data loss is important for your work.

The link often uses a redirected URL to hide the true landing page. For example, it may route through an off-brand URL shortener to seem harmless.

3. You Arrive at a Fake Login Page

Your browser lands on a nearly perfect replica of your email provider’s login screen. All branding, graphics, and text mimic the real site.![Fake login page example][]

Fake Login Page Designed to Steal Credentials

4. You Enter Your Credentials

Believing the site is legitimate, you enter your email address and password into the fake form.

Behind the scenes, the criminals immediately capture your credentials and can access your real inbox using this data.

5. The Scammers Leverage Your Account

With your username and password, the attackers log into your real email account. They can now browse inboxes or reset passwords for other services.

The criminals may enable email forwarding to collect copies of messages over time. Or they immediately start sending their own phishing scams to contacts.

In other cases, they may search for financial records, customer data, or other sensitive information. If they gain access to your entire system, deploying ransomware is also a risk.

6. You May Notice Unusual Activity

Odd activity in your email account may signal it has been compromised. Watch for unexplained forwarded messages, new rules, sent emails you did not send, or password reset notifications.

If you fall victim, immediately change your password and alert IT staff to scan for threats. But the most effective way to stop this scam is by recognizing it before entering credentials.

What to Do If You Fall Victim

If you entered your login credentials through a fake “Messages Blocked” page, take these steps to secure your account:

Reset Your Password

Change your email password immediately. Make it long and complex. Do this from a known safe device, not the compromised one.

Enable Two-Factor Authentication

Add an extra layer of security by requiring a confirmation code with each login. Generate backup codes in case you lose your device.

Check Forwarding Rules

Look for unauthorized forwarding rules sending copies of your email externally. Delete them.

Scan for Malware

Run a full virus scan to check for any Trojans, keyloggers, or other threats that may have been downloaded.

Contact Support

Alert your IT team or email provider to a potential breach of your account. They can implement extra protection measures like forced re-authentication.

Monitor Accounts Closely

Watch for any unusual security alerts about your online accounts, as hackers may have gained info to compromise other services. Change passwords frequently.

Educate Contacts

If any fraudulent emails were sent from your account, let all contacts know it was part of a phishing scam and they should ignore the messages.

Is Your Device Infected? Check for Malware

If your device is running slowly or acting suspicious, it may be infected with malware. Malwarebytes Anti-Malware Free is a great option for scanning your device and detecting potential malware or viruses. The free version can efficiently check for and remove many common infections.  

Malwarebytes can run on Windows, Mac, and Android devices. Depending on which operating system is installed on the device you’re trying to run a Malwarebytes scan, please click on the tab below and follow the displayed steps.

Frequently Asked Questions about the “Messages Blocked” Email Scam

1. What is the “Messages Blocked” email scam?

The “Messages Blocked” scam is a phishing email designed to trick users into revealing their login credentials. The email claims your inbox is full and messages have failed to send to multiple recipients. It provides a fake link to “fix” the problem and verify you’re not a robot. If you click the link, it takes you to a phony login page that steals your username and password when entered. Hackers then access your account to steal data, contacts, and launch additional attacks.

2. Who is behind the “Messages Blocked” scam?

Security researchers attribute the scam to the Trickbot cybercriminal group. They are involved in identity theft, financial fraud, and ransomware distribution. Trickbot sends these phishing emails globally but seems to target larger organizations in English-speaking countries.

3. How can I recognize a fake “Messages Blocked” email?

Warning signs of a scam email include mismatched sender/reply addresses, suspicious links, unknown sender domains, garbled sender names, irrelevant enclosed message subjects, and other oddities. Compare against a real system notification email to identify differences. The most important clue is an urgent call to action to click a link and verify you’re not a robot.

4. What happens if I click the link in a “Messages Blocked” scam email?

The link sends you to a convincing replica of your email login page. If you enter your credentials, criminals immediately capture them and gain full access to your inbox. They can steal data, contacts, and control your account.

5. How can I stay safe from the “Messages Blocked” phishing scam?

Never click links in suspicious emails, no matter how realistic they look. Instead, manually navigate to your email provider’s website through a known safe link to check your inbox. Implement security awareness training focused on phishing prevention. Enable multi-factor authentication for an extra account security layer.

6. What should I do if I entered my credentials through a “Messages Blocked” scam page?

Immediately change your email password, enable two-factor authentication, check for unauthorized forwarding rules, and scan your device for malware. Alert your IT team to a potential email breach. Monitor accounts closely for suspicious activity and reset passwords on other services if necessary.

7. How can organizations defend against the “Messages Blocked” phishing scam?

Implement ongoing end user education to avoid blind link clicking. Use email filtering tools to block dangerous file types, links, and sender addresses. Enforce MFA and limit public email exposure. Adopt cyber threat intelligence sharing to stay ahead of new variations. Maintain incident response plans for email breach containment.

The Bottom Line

The “Messages Blocked” phishing scam aims to overload recipients with urgency to click on a malicious link. With countless variations, this scam will likely continue evolving in the future.

Stay vigilant for any unusual emails and do not click on links from unverified senders. If concerned about storage limits, access your account directly through a known safe web page.

Implementing security awareness education, account monitoring, and email filtering are also key defenses against “Messages Blocked” and other phishing scams. But ultimately, organizational cyber-resilience depends on each individual avoiding these attacks at the human level.