How Overlooked Digital Assets Like Expired Domains Fuel Cyberattacks

When thinking about cybersecurity, businesses often focus on the most obvious threats: malware, ransomware, and data breaches. However, one growing risk is often overlooked: expired domains.

Expired domains are quickly becoming a critical vulnerability for cybercriminals to exploit. Once a domain expires, it becomes available for re-registration, and attackers have found ways to infiltrate systems, launch sophisticated phishing campaigns, and steal sensitive data.

How Cybercriminals Exploit Expired Domains

There are four main ways cybercriminals use expired domains, and they all center on trust. By acquiring the past domains of trusted entities, they’re able to capitalize on recognition.

Here’s what that looks like in practice:

1. Re-registering Expired Domains

When a domain expires, it’s released back into the market for re-registration. Cybercriminals actively monitor these expired domains—particularly those associated with reputable businesses, services, or brands. Once acquired, they can exploit the domain’s history to bypass security protocols.

Systems such as email servers or third-party services often trust expired domains because of their prior legitimacy.

2. Phishing Attacks with Expired Domains

Phishing is one of the most common tactics used by cybercriminals leveraging expired domains. Attackers can set up fake websites or email addresses under these domains to impersonate the original organization or brand.

For example, a hacker acquires an expired domain that once belonged to a vendor, then sends phishing emails to customers, requesting sensitive information or payments.

The familiarity of the expired domain makes phishing attempts harder to detect, increasing the likelihood of a successful breach.

3. Hosting Malware and Ransomware

Cybercriminals also exploit expired domains by using them to host malicious software. 

Attackers may:

• Create websites on the expired domain that distribute malware disguised as legitimate downloads.
• Redirect unsuspecting users to malicious sites that infect their systems with ransomware or spyware.

For example, if the expired domain previously hosted a popular software download, attackers could recreate the site, embedding malware in the downloads.

4. Catch-All Email Exploits and Identity Theft

Expired domains often have "catch-all" email servers set up, meaning any email sent to the domain—whether the address exists or not—will be received. 

This creates an opportunity for cybercriminals to intercept emails intended for the previous domain owner, including confidential information, invoices, and login credentials.

This intercepted data can then be used for identity theft, account takeovers, or further infiltration into the organization’s systems. Attackers are able to reset passwords, impersonate employees, or escalate their attack by gaining unauthorized access to sensitive accounts.

Case Studies: From Expired Domains to Cyber Weapons

In one real-world example, The Lazarus Group, a North Korean hacking collective, is known to have exploited thousands of expired domains to carry out widespread cyberattacks. Using domains that once hosted legitimate services or websites, they launched sophisticated malware campaigns and phishing attacks, tricking unsuspecting targets into downloading malicious files or entering sensitive data.

In another high-profile case, expired domains were used to infiltrate government systems. A domain, once used by a government contractor, was re-registered and used to impersonate the contractor, leading to phishing attacks on government employees.

These are just two examples of how domains tied to trusted entities—whether vendors, contractors, or partners—are prime targets for exploitation.

The Risks of Ignoring Expired Domains

When organizations lose ownership of once-trusted domains, they jeopardize the security of their own firms, as well as those they do business with.

Risks include:

• Financial Losses
• Reputational Damage
• Data Breaches and Identity Theft
• Supply Chain Instability

Improving the Security of Expired Domains

To protect against the risk of expired domains, organizations must actively monitor and manage their domain portfolios.

• Track Expiration Dates: Keep a close eye on the registration dates for all your domains and ensure timely renewals.
• Audit Domain Portfolios: Regularly audit your domains to identify unused or forgotten domains that should either be renewed or decommissioned securely.
• Use Domain Monitoring Tools: Leverage specialized tools that notify you when a domain associated with your organization or brand becomes available for re-registration.

In addition, it’s vital to take a zero trust stance with all domains—even internal ones. Only allow access to verified, trusted domains and always scrutinize unfamiliar sources.

Implement Multi-Factor Authentication (MFA) for all critical accounts, especially email, to prevent unauthorized access, even if login credentials are compromised.

Remember that your employees are often the first line of defense against phishing and domain-based threats. Provide regular training to ensure they recognize and avoid malicious attempts. Educate staff on how to handle suspicious emails, even if they seem to come from trusted sources.

Incorporating Domain Registrations Into Your Cybersecurity Strategy

The growing threat posed by expired domains underscores the need for a comprehensive and proactive cybersecurity strategy.

Consider the entire lifecycle of your domains, from registration to decommissioning. How can you build protections into every stage?

As cyberattacks become more sophisticated, ensure that domain management and email security are integrated into your broader cybersecurity architecture.

Expired domains may seem like a small threat in the grand landscape of cybersecurity, but their potential to fuel cyberattacks is real and growing. By understanding how they can be exploited and implementing proactive measures—such as robust domain management, MFA, and employee training—businesses can protect themselves from this often overlooked danger.

Act now to strengthen your organization’s cybersecurity profile.

About Us - Right Hand Technology Group

WHAT WE DO: We help U.S. Department of Defense (DoD) contractors and subcontractors ensure they can achieve Cybersecurity Maturity Model Certification (CMMC), a requirement for all DoD contractors.

In addition, we help our clients bridge the gap between Information Technology (IT), Cybersecurity and Compliance with a unique approach that includes a comprehensive gap analysis + an enterprise-style approach to individual departments. 

This includes supplying virtual Chief Information Security Officers (vCISOs) and virtual IT Directors (vITD) who utilize mature processes and frameworks + act as a true leader for your cybersecurity, compliance, and IT departments. 

We can also manage your IT and cybersecurity needs remotely.

If we haven’t already, I’d love to connect here on LinkedIn.