Ask any security professional where most cyberattacks start, and you’ll get the same answer: email. It remains the primary entry point for phishing and business email compromise (BEC), threats that rely on impersonation to manipulate human trust.

Most phishing attacks succeed because they look legitimate. Attackers impersonate trusted senders to deceive employees, customers, and partners into clicking malicious links, entering credentials, or wiring funds. When organizations implement DMARC (Domain-based Message Authentication, Reporting & Conformance) to stop exact-domain spoofing, attackers don’t abandon their efforts; they evolve.

Instead of forging a company’s domain, attackers register deceptive lookalike domains, exploit overlooked DNS misconfigurations, and use tactics designed to bypass traditional email security. These evolving attack methods make it clear that stopping exact-domain spoofing alone isn’t enough. Organizations need a multi-layered domain defense strategy to detect and mitigate all forms of domain-based threats before they escalate.

This guide explores:

• The various attack vectors bad actors use
• Why DMARC alone isn’t enough to stop threats
• How a comprehensive domain protection strategy defends against both exact and lookalike attacks before they cause harm

Most phishing attacks rely on one key element: a domain that looks real. Whether attackers are sending fraudulent emails or setting up fake websites, their goal is to mimic a trusted brand so that victims don’t question the legitimacy of their messages.

Attackers do this using two primary tactics:

• Exact-domain spoofing – Sending emails that appear to come from your real domain, exploiting weak authentication policies.
• Lookalike domains – Registering deceptive variations of your domain to send phishing emails, host fake websites, and steal credentials.

Sometimes, these tactics aren’t used in isolation. Sophisticated attackers combine both methods, spoofing emails from a trusted domain while simultaneously using lookalike domains to bypass email security, redirect victims, and execute large-scale fraud. See a real-life example of this below.

In an exact-domain spoofing attack, a fraudster fakes an email header to make their message appear as if it’s coming from your real domain (e.g., @yourcompany.com). To the recipient, the email looks legitimate even though it never actually originated from your infrastructure.

Most email clients only show the display name and sender address, not the underlying authentication details. This makes it easy for attackers to impersonate trusted senders –  whether it’s an internal executive, a supplier, or a customer support address –  when DMARC isn’t enforced.

• Looks legitimate – The email appears to come from your actual domain.
• Bypasses security (if DMARC isn’t enforced) – Without proper authentication policies, fraudulent emails are delivered just like real ones.
• Exploits urgency and authority – Spoofed emails often pose as executives or urgent requests (e.g., wire transfers, login resets).

In 2020, a sophisticated phishing campaign spoofed legitimate Microsoft domains to target Office 365 users. Attackers leveraged real Microsoft email addresses (e.g., @onmicrosoft.com) to send phishing emails that bypassed security checks.

Because Microsoft hadn’t fully enforced DMARC, these fraudulent emails were delivered to inboxes as if they were legitimate. The emails contained links to a convincing fake Office 365 login page, where victims unknowingly entered their credentials, granting attackers full access to their accounts.

This attack highlights the direct consequences of not enforcing DMARC at p=reject – attackers can send emails from a real domain, tricking recipients into handing over sensitive data.

The only way to block exact-domain spoofing is by enforcing DMARC (p=reject), ensuring that only authorized senders can use your domain.

But here’s the problem: while trusted domains are first to be spoofed, attackers don’t stop when DMARC is in place. Instead, they adapt their methods, which is where lookalike domains come into play.

Once DMARC prevents exact-domain spoofing, attackers pivot - registering fake versions of your domain that closely resemble the real thing. These lookalike domains don’t just enable phishing emails; they also power fraudulent websites, fake login pages, and scam operations that trick your customers and employees.

Attackers register domain names that are visually similar to yours, making it easy to deceive recipients at a glance. Here’s how they do it:

Cybercriminals are constantly evolving their tactics to bypass traditional defenses. When exact-domain spoofing is blocked by DMARC and lookalike domains are identified and neutralized, attackers still don’t stop their efforts to impersonate - instead, they shift to exploiting weaknesses in domain infrastructure.

DNS misconfigurations are one of the most overlooked attack surfaces in cybersecurity. Many organizations set up DNS records once and forget about them, leaving behind abandoned, misconfigured, or poorly secured entries that attackers can exploit.

By hijacking vulnerable DNS records, attackers can:

• Send phishing emails from legitimate subdomains that pass SPF, DKIM, and DMARC checks.
• Host fraudulent websites on abandoned subdomains to steal credentials and payments.

These attacks don’t rely on traditional spoofing. They abuse real, authorized domains, making them harder to detect and more convincing to victims.

Attackers don’t rely on just one method to impersonate your brand - they pivot, adapt, and exploit whatever gaps they can find. DMARC enforcement stops exact-domain spoofing, DNS security hardens infrastructure, and brand monitoring detects external threats but these defenses can’t operate in isolation.

To illustrate why a layered approach is essential, let’s use a simple analogy. Think of your domain like a house: different security gaps represent different entry points that attackers can exploit. Locking the front door won’t help if the windows are open or the foundation is weak.

To fully protect against domain impersonation, organizations need a solution that enables multi-layered defense by providing:

• Protection from exact-domain spoofing at the source via DMARC
• Ongoing DNS configuration monitoring to identify infrastructure exploits 
• Detection and takedown of lookalike domains before they can be used in phishing campaigns via email or web

No single control is enough to stop attackers who constantly shift tactics. That’s why Red Sift OnDMARC, DNS Guardian, and Brand Trust work together, providing the layered protection needed to secure your domain from every angle.

Securing a domain starts with DMARC enforcement, ensuring that only authorized senders can use the domain for email. Without it, attackers can send phishing emails that appear to come from a trusted source, tricking recipients into taking action.

Think of this as locking the front door of your house. If attackers can forge emails using a legitimate and trusted domain name, they don’t need to trick people with lookalikes - they can walk right in through an open door.

Red Sift OnDMARC is an automated DMARC application that helps organizations take back control of their email reputation and stop unauthorized use of their email-sending domains. By providing step-by-step implementation guidance, hosted email protocol management, as well as clear DMARC reports that provide insight into sending services and domain health, it helps global brands reach DMARC enforcement (p=reject) quickly and effectively.

With Red Sift OnDMARC, you can:

• Shut down unauthorized senders by blocking phishing emails that falsely claim to come from the organization’s domain.
• Enforce authentication at scale by ensuring only approved mail servers can send on behalf of the domain.
• Leverage advanced hosted authentication capabilities to make management of your email records easy and straightforward.
• Get real-time visibility into sources failing authentication with detailed forensic reporting.

But locking the front door isn’t enough if attackers can crawl through an open window, which is exactly what happens when DNS misconfigurations are left unchecked.

Even with DMARC fully enforced, misconfigured or abandoned DNS records can leave an organization exposed. Attackers look for these weaknesses, using subdomain hijacking, SPF misconfigurations, and MX record abuse to bypass authentication checks.

This is like reinforcing the windows and fixing cracks in the foundation. Even if the front door is secure, an attacker will find another way in if there’s a weak spot elsewhere.

That’s why Red Sift OnDMARC has the industry’s only built-in DNS configuration monitoring that can identify and stop malicious mail that bypasses DMARC, including spam from domain takeovers and SubdoMailing.

DNS Guardian helps to:

• Identify subdomains with misconfigured or orphaned DNS records that are susceptible to being taken over by malicious actors.
• Detect subdomains already controlled by bad actors through CNAME takeover or legitimate CNAME delegation with poisoned SPF records.
• Provide actionable recommendations and remediation steps to address identified risks and strengthen domain security.

Securing your domain and DNS infrastructure shuts down direct impersonation, but attackers don’t need access to your systems to exploit your brand. Instead, they create deceptive lookalike domains designed to mislead customers, partners, and employees.

If OnDMARC is the lock and DNS Guardian secures the foundation, Brand Trust is the neighborhood watch, identifying threats beyond your perimeter. Even when your domain is protected, attackers can still set up deceptive lookalike domains designed to mislead customers, partners, and employees.

Red Sift Brand Trust is an AI-driven solution designed to protect brands by identifying and monitoring lookalike domains that imitate legitimate assets. It leverages advanced algorithms and computer vision to detect unauthorized use of brand elements (such as logos, faces, keywords), enabling swift enforcement actions against such abuse. 

Red Sift Brand Trust enables:

• Best-in-class detection capabilities that spot and monitor newly registered domains that resemble the organization’s brand.
• Automated lookalike assessment with AI-powered risk scoring and agentic architecture, continuously analyzing risk factors like logo detection, executive faces, keyword analysis, and page classification to classify lookalikes into risk categories.
• Rapid takedown to eliminate threats before they can be weaponized. 
• Quick and simple setup with no changes to MX or other mail records.

When used in tandem, Red Sift OnDMARC and Red Sift Brand Trust create a “full-spectrum” defense: emails purportedly from your genuine domains will not be delivered unless properly authenticated, and emails or links from lookalike domains are identified and can be blocked or removed. This dramatically reduces the attack surface for phishing. An attacker’s choices get whittled down to nothing very effective – they can’t spoof the real domain (DMARC blocks it), and if they try to use a fake domain, there’s a high chance Brand Trust has already flagged and initiated action against it. 

Organizations relying on just one approach (for example, only a DMARC solution, or only a domain monitoring service) leave themselves exposed to the vector not covered. For instance, a company that only monitors for lookalike domains but hasn’t implemented DMARC could still be spoofed by a hacker simply sending emails from the company’s real domain. Conversely, a company with DMARC set up but no lookalike domain monitoring might fail to catch attackers deceiving users with near-identical domain names. That’s why the Red Sift philosophy – and increasingly the industry consensus – is that protocol-based security together with continuous detection and monitoring provides far stronger protection than either one alone​.

Protecting your domain against impersonation attacks requires more than just one solution. OnDMARC, DNS Guardian, and Brand Trust provide a comprehensive, layered defense that eliminates attack surfaces before they can be exploited.

Request a demo today to see how Red Sift can help your organization stay ahead of evolving threats.