How to recognize fake emails like "404 Mail Delivery Failed"

What is "404 Mail Delivery Failed"?

During our analysis of the email we found that it is a phishing attempt (a phishing email). Scammers who crafter this email aim to trick recipients into believing they have received a notification from an email service provider. Therir ultimate goal is to steal personal information from recipients.

More about the "404 Mail Delivery Failed" scam email

The subject line of the email contains a message stating that the recipient has five new unread messages. The email itself claims that there was a mail delivery failure for an incoming message from a sender. It urges the recipient to validate their email storage quota, which is supposedly at 29.4GB.

Also, this scam email includes a fake user ID and a message ID and contains "Release" and "Deliver All Messages" hyperlinks. Furthermore, it lists several quarantined emails with details such as each message's recipient, subject, and date. Scammers behind this scam seek to lure recipients into opening a phishing website via one of the provided links.

On that phishing page (masquerading as a legitimate Webmail login page) potential victims are requested to enter their email account login credentials, such as their email address and password, and click "Submit". All "submitted" information is sent to scammers who can use it for malicious purposes.

When scammers successfully pilfer login credentials, they can log into the account and send deceptive emails to the victim's contacts. Also, they can search for personal information, reset passwords for linked accounts, and engage in other malicious activities.

Moreover, scammers may try to use the stolen credentials to access other accounts and sell the compromised login information and any other collected data to other criminals. For these reasons, it is crucial to avoid responding to suspicious emails or providing personal information on associated websites.

Threat Summary:

Name	404 Mail Delivery Failed Email Scam
Threat Type	Phishing, Scam, Social Engineering, Fraud
Fake Claim	Recpients have 5 new unread messages
Related Domain	bronze-platypus-m4mvt8.mystrikingly[.]com
Detection Names	Abusix (Spam), Trustwave (Phishing), Full List Of Detections (VirusTotal)
Disguise	Letter from an email service provider
Symptoms	Unauthorized online purchases, changed online account passwords, identity theft, illegal access of the computer.
Distribution methods	Deceptive emails, rogue online pop-up ads, search engine poisoning techniques, misspelled domains.
Damage	Loss of sensitive private information, monetary loss, identity theft.
Malware Removal (Windows)	To eliminate possible malware infections, scan your computer with legitimate antivirus software. Our security researchers recommend using Combo Cleaner. ▼ Download Combo Cleaner To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.

Similar scam emails in general

These fraudulent messages are designed to trick recipients into revealing sensitive information, such as passwords or financial details. They often mimic legitimate organizations and include links or attachments. Falling for these scams can lead to identity theft, financial loss, and compromised accounts.

It is important to mention that cybercriminals often use email as a route to deliver malware. Some examples of emails targeting personal information are "Adobe - You Have Received New Files", "Bank Transfer Accounting Copy", and "Internet Corporation For Assigned Names And Numbers (ICANN)".

How do spam campaigns infect computers?

Threat actors behind emails intended to deliver malware aim to trick users into downloading malicious attachments, which can include executables, Office documents, PDFs, executables, script files, or others. Malware is executed when users open these files or follow prompts like enabling macros in infected documents. Also, emails can include links used to distribute malware.

When users click on links in these emails, they may be directed to fake websites designed to trick them into downloading malware or trigger automatic malware downloads.

How to avoid installation of malware?

Carefully inspect emails with links or attachments. If the emails seem irrelevant, unexpected, or suspicious—especially from unknown senders—avoid opening their contents. Always download files or software from official websites or trusted app stores, and do not trust ads, pop-ups, or links on questionable sites.

Ensure your operating system and software are up to date, and use a trusted security program. If you have already opened malicious attachments, we recommend running a scan with Combo Cleaner Antivirus for Windows to automatically eliminate infiltrated malware.

Text presented in the "404 Mail Delivery Failed" email letter:

Subject: You have 5 new unread messages pending by administrator.

404 Mail delivery failed: Incoming message from sender

You have 5 new unread messages pending by administrator, validate E-mail storage Quota to 29.4GB.
Date: 2024/9/30 23:02:54
User: ********
Message ID: UTC9@50FU3>

Click on Release or Deliver or Release All these message(s) to your inbox folder: Deliver All Messages

Quarantined email
Recipient:    Subject:    date:
Release ******** Mail Delivery System : Re: Statement_0619 & Pending Invoices    2024/9/30 23:02:54
Release ******** Mail Delivery System : FW: B/L Copy, Packing List & Commercial INV    2024/9/30 23:02:54
Release ******** Mail Delivery System : RE:  Order.4479 List 2024/9/30 23:02:54
Release ******** Mail Delivery System : FW: SWIFT Notificación BBVA net cash    2024/9/30 23:02:54
Deliver All  messages

Note: This message was sent by the system for notification only.  Please do not reply  

If this message lands in your spam folder, please move it to your inbox folder for proper interagtion:

Phishing website used in this scam:

Instant automatic malware removal: Manual threat removal might be a lengthy and complicated process that requires advanced IT skills. Combo Cleaner is a professional automatic malware removal tool that is recommended to get rid of malware. Download it by clicking the button below:
▼ DOWNLOAD Combo Cleaner By downloading any software listed on this website you agree to our Privacy Policy and Terms of Use. To use full-featured product, you have to purchase a license for Combo Cleaner. 7 days free trial available. Combo Cleaner is owned and operated by Rcs Lt, the parent company of PCRisk.com read more.

Quick menu:

• What is 404 Mail Delivery Failed phishing email?
• Types of malicious emails.
• How to spot a malicious email?
• What to do if you fell for an email scam?

Types of malicious emails:

Phishing Emails

Most commonly, cybercriminals use deceptive emails to trick Internet users into giving away their sensitive private information, for example, login information for various online services, email accounts, or online banking information.

Such attacks are called phishing. In a phishing attack, cybercriminals usually send an email message with some popular service logo (for example, Microsoft, DHL, Amazon, Netflix), create urgency (wrong shipping address, expired password, etc.), and place a link which they hope their potential victims will click on.

After clicking the link presented in such email message, victims are redirected to a fake website that looks identical or extremely similar to the original one. Victims are then asked to enter their password, credit card details, or some other information that gets stolen by cybercriminals.

Emails with Malicious Attachments

Another popular attack vector is email spam with malicious attachments that infect users' computers with malware. Malicious attachments usually carry trojans that are capable of stealing passwords, banking information, and other sensitive information.

In such attacks, cybercriminals' main goal is to trick their potential victims into opening an infected email attachment. To achieve this goal, email messages usually talk about recently received invoices, faxes, or voice messages.

If a potential victim falls for the lure and opens the attachment, their computers get infected, and cybercriminals can collect a lot of sensitive information.

While it's a more complicated method to steal personal information (spam filters and antivirus programs usually detect such attempts), if successful, cybercriminals can get a much wider array of data and can collect information for a long period of time.

Sextortion Emails

This is a type of phishing. In this case, users receive an email claiming that a cybercriminal could access the webcam of the potential victim and has a video recording of one's masturbation.

To get rid of the video, victims are asked to pay a ransom (usually using Bitcoin or another cryptocurrency). Nevertheless, all of these claims are false - users who receive such emails should ignore and delete them.

How to spot a malicious email?

While cyber criminals try to make their lure emails look trustworthy, here are some things that you should look for when trying to spot a phishing email:

• Check the sender's ("from") email address: Hover your mouse over the "from" address and check if it's legitimate. For example, if you received an email from Microsoft, be sure to check if the email address is @microsoft.com and not something suspicious like @m1crosoft.com, @microsfot.com, @account-security-noreply.com, etc.
• Check for generic greetings: If the greeting in the email is "Dear user", "Dear @youremail.com", "Dear valued customer", this should raise suspiciousness. Most commonly, companies call you by your name. Lack of this information could signal a phishing attempt.
• Check the links in the email: Hover your mouse over the link presented in the email, if the link that appears seems suspicious, don't click it. For example, if you received an email from Microsoft and the link in the email shows that it will go to firebasestorage.googleapis.com/v0... you shouldn't trust it. It's best not to click any links in the emails but to visit the company website that sent you the email in the first place.
• Don't blindly trust email attachments: Most commonly, legitimate companies will ask you to log in to their website and to view any documents there; if you received an email with an attachment, it's a good idea to scan it with an antivirus application. Infected email attachments are a common attack vector used by cybercriminals.

To minimise the risk of opening phishing and malicious emails we recommend using Combo Cleaner Antivirus for Windows. 

Example of a spam email:

What to do if you fell for an email scam?

• If you clicked on a link in a phishing email and entered your password - be sure to change your password as soon as possible. Usually, cybercriminals collect stolen credentials and then sell them to other groups that use them for malicious purposes. If you change your password in a timely manner, there's a chance that criminals won't have enough time to do any damage.
• If you entered your credit card information - contact your bank as soon as possible and explain the situation. There's a good chance that you will need to cancel your compromised credit card and get a new one.
• If you see any signs of identity theft - you should immediately contact the Federal Trade Commission. This institution will collect information about your situation and create a personal recovery plan.
• If you opened a malicious attachment - your computer is probably infected, you should scan it with a reputable antivirus application. For this purpose, we recommend using Combo Cleaner Antivirus for Windows.
• Help other Internet users - report phishing emails to Anti-Phishing Working Group, FBI’s Internet Crime Complaint Center, National Fraud Information Center and U.S. Department of Justice.

Frequently Asked Questions (FAQ)

Why did I receive this email?

Scammers typically send the same phishing email to many recipients, using email addresses gathered from data breaches or other sources. These emails are usually generic and lack personalization.

I have provided my personal information when tricked by this email, what should I do?

If you have shared any account credentials, update all your passwords right away and enable two-factor authentication for added security. Additionally, monitor your accounts for any unusual activity.

I have downloaded and opened a malicious file attached to an email, is my computer infected?

The likelihood of infection depends on the type of file you opened. For example, opening a compromised Word document without enabling macros may prevent malware activation. However, if you opened an infected executable file, your system is likely compromised.

I have read the email but did not open the attachment, is my computer infected?

Simply reading or opening emails is harmless. Infections occur when malicious attachments are opened or fraudulent links are clicked.

Will Combo Cleaner remove malware infections that were present in email attachment?

Yes, Combo Cleaner can detect and remove malware. However, advanced malware often buries itself deep within the system. This makes performing a full system scan crucial to find and eliminate any hidden threats.

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