What Is Email Spoofing & How to Protect Your Organization

Brought to you by Gilad David Maayan  

What Is Email Spoofing?

Email spoofing is a fraudulent technique used by spammers and scammers to impersonate a sender's email address in order to deceive the recipient into treating the message as legitimate. 

In email spoofing, the email's sender address is forged or modified to appear like it is coming from a trusted or familiar source, such as a legitimate company, organization, or even a family member or friend.

Spoofed emails are often used for phishing attacks, where the attacker tries to trick recipients into sharing or exposing sensitive information such as passwords, credit card details, or other personal information. They may also contain malicious attachments or links that can infect the recipient's computer with malware.

Attackers are able to spoof emails because the Simple Mail Transfer Protocol (SMTP) used to send emails doesn't verify the sender's identity. However, there are techniques that can be used to detect and prevent email spoofing, such as SPF (Sender Policy Framework) and DMARC (Domain-Based Message Authentication, Reporting, and Conformance).

What Is the Relation Between Phishing, Spoofing and BEC?

Spoofing and phishing are related but distinct concepts. Spoofing refers to the act of falsifying an email's sender address to make it appear as if it were sent by someone else. Phishing, on the other hand, is a social engineering attack in which an attacker tricks a recipient into divulging sensitive information by posing as a trusted entity. Phishing prevention is a top priority for most security teams.

Email spoofing and Business Email Compromise (BEC) are two types of email-based attacks that are frequently used by cybercriminals to dupe users into revealing sensitive information or transferring funds. BEC is a type of email-based attack where an attacker targets a specific organization or individual, typically using email spoofing to make their email appear to have come from a trusted individual within the organization. 

The attacker may impersonate a company executive or a trusted partner to trick the recipient into transferring funds or revealing sensitive information. BEC attacks are often highly targeted and can be very effective, as they rely on social engineering tactics to trick the recipient into taking action.

How Does Email Spoofing Work?

Email spoofing works by manipulating the email header fields to make it appear as if the email was sent from a different sender. The email header contains important information about the email, including the sender, recipient, subject, date, and other metadata. The attacker can modify one or more of these fields to create a spoofed email.

There are various ways attackers can forge email fields using scripts. One common method is to use a scripting language such as Python to create a program that sends emails using the Simple Mail Transfer Protocol (SMTP). The attacker can then modify the script to include a different sender address than their own.

In addition to modifying the sender field, attackers may also use other techniques to make the email appear more legitimate. For example, they may use a domain that is similar to the legitimate domain of the sender, such as substituting a lowercase "L" for an uppercase "I". This is known as domain spoofing and can be used to trick the recipient into believing that the email is legitimate.

Attackers may also use social engineering techniques in conjunction with email spoofing. For example, they may use a subject line that is urgent or compelling to entice the recipient to open the email and follow any instructions contained within, such as clicking on a link or downloading an attachment.

How to Stop Email Spoofing Attacks

The following techniques can help protect against spoofing and other email-based security threats.  

Implement Email Security Protocols

Email security protocols such as DKIM, DMARC, and SPF can help reduce spam and protect against spoofing by verifying the authenticity of the sender's domain:

• DKIM (Domain Keys Identified Mail) is a cryptographic authentication protocol that enables the receiver to verify that a given email was sent by an authorized sender and that the email contents were not modified in transit.

• SPF (Sender Policy Framework) is another email authentication protocol that helps detect and prevent email spoofing by verifying that the sender is authorized to use the domain in the email's "From" field.

• DMARC (Domain-Based Message Authentication, Reporting, and Conformance) builds upon DKIM and SPF to provide a more comprehensive email authentication solution. It allows domain owners to specify how they want emails that fail authentication checks to be handled, such as being quarantined or rejected.

Leverage Email Security Gateways

An email security gateway is a software or hardware-based tool that is designed to monitor and secure email traffic. It can protect against email spoofing by using various technologies to verify the authenticity of email senders and block suspicious emails before they reach the recipient's inbox. It can also use machine learning algorithms to detect and block phishing emails.

Email security gateways work at the network layer to enforce email security policies and typically include capabilities such as spam filtering and malware blocking. This approach means the user experience is unaffected.

Authenticate Senders with Reverse IP Lookups

A reverse IP lookup is a technique used to determine the domain name associated with a specific IP address. Website owners can use it to protect against email spoofing by checking if the IP address associated with an incoming email matches the IP address of the sender's domain. If they don't match, it may be an indication of email spoofing, and the email should be treated with caution or blocked.

Implement Cybersecurity Awareness Training

Training employees in cybersecurity awareness can help them recognize and handle spoofing attempts by teaching them how to identify suspicious emails and phishing attempts. They can learn how to check email headers, identify inconsistencies in sender information, and avoid clicking on links or downloading attachments from unknown sources. Regular training can also help keep employees up-to-date with the latest spoofing techniques and best practices for protecting against them.

Use Antimalware 

Antimalware is software designed to detect, prevent, and remove malicious software from computers and networks. It can block spoofing emails by detecting and blocking malware contained within the email or its attachments.

Conclusion

In conclusion, email spoofing is a serious threat to individuals and organizations alike. Attackers use this technique to impersonate trusted entities and deceive recipients into divulging sensitive information or downloading malware. 

However, there are several measures that organizations can take to protect themselves against email spoofing, such as implementing email authentication protocols like SPF, DKIM, and DMARC, using email security gateways, conducting regular cybersecurity awareness training for employees, and using antimalware software. 

By implementing these best practices, organizations can reduce the risk of email spoofing and protect their sensitive information and assets. It is important for individuals and organizations to stay vigilant and stay up-to-date with the latest spoofing techniques and cybersecurity best practices.

Gilad David Maayan is a technology writer producing thought leadership content that elucidates technical solutions for developers and IT leadership. 

Image: vectorjuice on freepik

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