How does email spoofing work?

Email spoofing works by configuring sender addresses to look like they are from an internal domain or a familiar external domain, using exact sender names, and manipulating the Reply-To field in the email header to direct emails with potentially confidential information straight to a fake account.

What is Email Spoofing? How to Prevent Email Spoofing

Q: What is email spoofing?

Email spoofing is a technique scammers use to make fraudulent emails appear as if they came from a known entity.

By now, most employees know misspellings, fishy links, and questionable attachments are the telltale signs of an email scam. While this is notable evidence of successful employee education, scams and cyberattacks have only gained sophistication. Even the most savvy employees can fall for a clever email spoofing campaign.

According to IBM’s Cost of a Data Breach Report, the average cost per compromised record has steadily increased. In 2020, the average breach costs organizations $3.92 million. Since spoofing is often the first step in a costly breach, your business has a major incentive to prevent email spoofing attacks before they occur. In this piece, we’ll define what email spoofing is and offer expert tips for overall preventing email spoofing.

The Evolution of Email Spoofing

In spite of the few email filtering options available, spoofing morphed into a major global security issue by the 2000s. In response, the European Union released a Directive on Privacy and Electronic Communications in 2002, making it illegal to send unsolicited communications without the prior consent of the recipient.

The US followed suit in 2004, but these regulations overwhelmingly failed at completely eliminating spoofing and other types of email-based spam. Even with today’s advanced cybersecurity tools, 3.1 billion domain spoofing emails are sent per day, and over 90% of cyberattacks start with an email message.

Configuring sender addresses to look like they are from an internal domain or a familiar external domain: These addresses may look like supplier addresses, coworker addresses, or even governmental institution addresses.
Using exact sender names (JeffBezos@technologybusiness123.com),
similar sender names (JeffBizos@technologybusiness123.com),
lookalike or cousin domains (JeffBezos@amaz0n.com) to fool unsuspecting recipients or
exact domain spoofs (JeffBezos@amazon.com).
Manipulating the Reply-To field in the email header to direct emails with potentially confidential information straight to a fake account.

Outgoing email servers cannot detect whether a sender’s email address is legitimate.
Email API endpoints permit attackers to send emails using addresses that don’t exist.
Secure Policy Framework (SPF) can identify most spoofed emails, but attackers rely on the fact that the domain holder must specify all IP addresses authorized to send messages and might miss a few.
Attackers also know that even if IP addresses don’t meet an organization’s standards, attackers know that recipients rarely validate that an email has a “PASS” SPF status before hitting reply.

SPF is limited to 10 lookups. Many companies have multiple cloud-based services that can send messages, causing companies to bump up against this restriction almost immediately.
Records only apply to specific Return-Path domains and not those found in the ‘from’ address. This leaves a window for scammers to create messages that will authenticate, allowing scammers to spoof the visible “From” field.

Example:

From: Bank of America <billpay@billpay.bankofamerica.com>

Return-Path:
<recepcionfacturas@grupo-emsa.com.mx>

Subject: Your eBill Due Date Is Approaching

Training only goes so far一employees aren’t actively looking for phishing emails like security teams might be, and they don’t always abide by your company’s security regulations.
Employees don't recognize the nuance of every threat, so education can only be one step in a robust cybersecurity process.
Phishing tests can help, but scammers are constantly developing new techniques and leveraging social engineering, making it tough to test for every possibility and all it takes is one lapse of concentration.

How to Prevent Email Spoofing Successfully

Email is now completely enmeshed with work, making strategies to prevent email spoofing a baseline requirement in any organization.

Commonly used email spoofing protection strategies like SPF, DKIM, and DMARC have severe limitations, even when employed simultaneously. In fact, as more companies adopt those tactics, attackers launch more domain impersonation attacks that SPDF, DKIM, and DMARC cannot protect against.

Modern prevention against email spoofing requires a blended approach using artificial intelligence and human insights.

Wading through thousands of emails a day and picking up on new abnormalities is an impossible task for humans alone, but not for computers.

Learn more about the effectiveness of using human and AI collaboration to combat modern phishing threats.

AI-powered anomaly detection tools analyze both user behavior patterns and email metadata, helping the algorithms and platform better identify and respond to new spoofing techniques.

To react to spoofed emails quickly and effectively, organizations must layer advanced mailbox anomaly detection on top of SPF, DKIM, DMARC, and training.

Learn more about advanced mailbox-level anomaly detection.

How To Prevent Email Spoofing With An Advanced Email Security Platform

IRONSCALES is a pioneer in the cybersecurity space, detecting email spoofing and other advanced threats better than any other platform on the market.

The IRONSCALES platform includes mailbox-level anomaly detection, anti-phishing tools, and protection against business email compromise (BEC). And with intelligent automation, IRONSCALES can stop phishing emails before they even hit your employees’ inboxes.