Email spoofing refers to a type of cyber attack where a hacker sends an e-mail that appears to have been sent from a trusted source. Because people believe an email has been sent from a trusted sender, email spoofing is a common tactic in spam and phishing campaigns. Email spoofing is used to trick recipients into the opening and responding to messages.
Email spoofing: Why it is important
While most spam emails are easily identifiable and can be deleted, some types can pose security threats and cause serious problems. A spoofed email might pretend to come from a popular shopping site and ask the recipient for sensitive information, such as passwords or credit card numbers.
A spoofed email could also contain a link to install malware on the user’s computer if clicked. A common example of business email compromise (BEC) involves spoofing emails from the chief executive officer (CEO) or chief financial officer (CFO) of a company requesting a wire transfer or internal system access credentials.
Email spoofing: Reasons
Phishing is not the only reason attackers use spoofed emails:
- You can hide the real identity of the fake sender.
- Blocklists and spam filters can be bypassed. Users can minimize this threat by blocklisting internet service providers (ISPs) and Internet Protocol (IP) addresses.
- To obtain confidential information, pretend to be a friend or colleague.
- To get credit card data, pretend to be a trustworthy organization.
- Commit identity theft by impersonating a targeted victim and requesting personally identifiable information (PII).
- Do it to the reputation of the sender.
- Spread malware in attachments.
- Conduct a man-in-the-middle (MitM) attack to seize sensitive data from individuals and organizations.
- Access sensitive data that third-party vendors have collected
What is the difference between domain impersonation, spoofing, and phishing?
As part of a phishing attack, cybercriminals often resort to spoofing. Phishing is the use of spoofing to get data. This involves pretending an email address and then sending an email that appears to be coming from a trusted source. The aim is to get victims to click on a link, or to download an attachment that will infect their systems with malware.
Domain impersonation is another term for spoofing. This is where an email address is used that looks similar to another. In domain impersonation, an email may come from an address such as email@example.com, while, in a spoofing attack, the fake sender’s address will look genuine, such as firstname.lastname@example.org.
How email spoofing works
Email spoofing is possible with a simple mail transfer protocol (SMTP) server. This server can also be used to access common email platforms such as Outlook and Gmail. After an email message has been composed, the scammer may forge the fields such as the FROM and REPLY-TO addresses. The email appears to have been sent from the fake address when it is received by the recipient.
Because SMTP doesn’t allow for authentication of addresses, this is possible. Although there are protocols and methods to stop email spoofing, they have not been widely adopted.
How to detect if an email is spoofed
It is unlikely that users will notice a fake email if it does not look suspicious. If users feel that something is amiss, they can inspect the email source code. The recipients can then trace the sender’s IP address back to the original sender by opening the email source code.
A user can confirm that a message has passed the Sender Policy Framework (SPF). SPF is an authentication protocol that is included in many email platforms as well as email security products. Users’ email settings may allow messages marked as “soft failure” to still be delivered to their inbox. Soft failure can indicate an unlegitimate sender.
Learn more about the methods security professionals use to detect phishing emails and email spoofing.
9 ways to stop email spamming
Businesses and users can block email spoofers from accessing their systems in many ways.
1. Install an email security gateway
Email security gateways prevent businesses from receiving outbound or inbound emails with suspicious elements. They also ensure that they comply with security policies. Some gateways offer additional functions, but all can detect most malware, spam, and phishing attacks.
2. Antimalware software is recommended
Software programs can block and identify suspicious websites, detect spoofing attacks, and stop fraudulent emails from reaching user inboxes.
3. Encrypt your emails to protect them
Email signing certificates encrypt emails and allow only the intended recipient access to the content. Asymmetric encryption uses a public key to encrypt the email and a private key that is owned by the recipient to decrypt the message. A digital signature can be used to verify that the sender is legitimate. In environments without broad encryption in place, users can learn to encrypt email attachments.
4. Use email security protocols
Infrastructure-based email security protocols can reduce threats and spam by using domain authentication. Businesses can also use DomainKeys Identified Mail to add a layer of security and a digital signature to their mail. Domain-based Message Authentication Reporting and Conformance can be used to determine the correct actions when messages fail to pass under DKIM and SPF.
5. To authenticate senders, use reverse IP lookups
Reverse IP Lookup confirms that the sender is real and verifies the source of the email by identifying the domain associated with the IP address.
Site owners may also want to publish a domain name system record (DNS), which states who can send an email on behalf of their domain. Before the email body can be downloaded, messages are checked and rejected.
6. Train employees in cyber awareness
On top of software-based anti-spoofing measures, businesses must encourage user caution, teaching employees about cybersecurity and how to recognize suspicious elements and protect themselves. Users can be taught simple educational programs that teach them how to spot and deal with spoofing techniques and what to do if they are caught. Training should be ongoing so that the materials and methods can be updated as new threats emerge.
7. Beware of spoofed email addresses
Often, the email addresses that users use to communicate are familiar and predictable. It is possible to learn how to spot suspicious or unusual email addresses and verify the origin of emails before you interact with them. Users must be vigilant as attackers often employ the same tactics repeatedly.
8. Don’t give out any personal information
Even if fake emails make it into inboxes, the real harm is done when users respond with personal information. Email spoofing can be greatly reduced by making it a practice not to disclose personal information in an email.
9. Avoid unfamiliar attachments and links
Be wary of links and attachments that may be suspicious. Users should always inspect every email carefully before opening attachments or links.