DNS Hijacks Hit Big Brands: What Your Team Misses

Even Big Enterprises Get Hijacked: Lessons from Recent DNS Attacks - posted

Introduction

‍No one is immune to domain based threats because even some of the largest and most trusted organizations have learned this the hard way. In the past year, attackers have managed to hijack thousands of legitimate domains and subdomains belonging to major brands and institutions by exploiting overlooked DNS vulnerabilities. For example, a massive 2024 campaign dubbed “ResurrecADS” covertly took control of over 8,000 domains and 13,000 subdomains, affecting companies from eBay and Symantec to UNICEF, by exploiting abandoned DNS records. Another incident saw subdomains of the U.S. Centers for Disease Control (CDC) and large universities get hijacked due to “dangling” DNS entries, which are old records pointing to now defunct services, that attackers then used to host scam content. These high profile breaches highlight a clear warning: if your DNS infrastructure has gaps, attackers will find them regardless of your organization’s size.

The Mechanics of the Attack

‍The common thread in these incidents is that DNS, the system that translates human friendly domains to actual server addresses, became the avenue for attack. By breaching or manipulating DNS configurations, attackers can silently redirect users to malicious destinations while everything appears normal on the surface. Crucially, this often happens before any malware is deployed or any software vulnerability is exploited. As one industry expert put it, “Many compromises don’t begin with an exploit. They begin with controlling what users resolve.” In other words, the very first observable sign of an intrusion may be a subtle DNS change, which is why security teams are increasingly treating DNS as a high leverage detection layer for early warning signals.

The Cascading Consequences

‍Once attackers control a domain or subdomain, they inherit the trust users place in that name, and the consequences can cascade quickly. They can set up convincing phishing pages, for example a fake login portal under your real brand’s domain, to steal credentials or serve malware from a seemingly legitimate URL. Email security can be undermined too because a hijacked subdomain is technically “allowed” by that organization’s email settings, so phishing emails sent from it may bypass checks like SPF or DKIM and appear authentic. In the blink of an eye, a misconfigured DNS record turns into an open door for business email compromise, fraud, or deeper breaches. For the victim organization, the fallout includes lost customer trust and potential regulatory penalties if user data is compromised, plus an extended incident response nightmare to clean up the damage.

Why DNS Is the Earliest Alarm

‍The silver lining is that DNS anomalies can be spotted and acted upon, but only if organizations have a clear view of their own DNS footprint. During any suspected incident, one of the first questions a team must answer is, “Is this normal, or is this an incident?” Too often, teams lack an up to date inventory of their domains, subdomains, and DNS records to confidently answer that question. This is why establishing a baseline DNS scan is so important. A baseline gives you a clean, current picture of all your legitimate DNS records and their expected configurations. Later, when a change occurs, say a new subdomain appears or an important host’s IP address suddenly points to a different server, you can quickly determine if it is an approved change or a red flag. The first baseline scan essentially draws the line between “normal” and “suspicious” for your environment so you can move faster when an anomaly shows up.

Continuous Monitoring for Changes

‍Beyond the initial baseline, continuous monitoring is key. Attackers could strike at any time, or an accidental DNS misconfiguration might occur during a routine update, so you want eyes on your DNS records 24/7. Automated DNS monitoring will alert you to any changes or unusual activity in real time, such as:

• Unexpected DNS record changes: This includes an IP address for your website or API suddenly pointing to a new server, or your MX mail record being redirected to an unfamiliar host.
• Unauthorized new DNS entries: Detection of subdomains or records that were not there before, which could indicate an attacker or rogue service adding entries without your knowledge.
• Lookalike domain alerts: Flags if domains suspiciously similar to your organization’s, such as typos or homoglyphs of your name, are registered and active as these often signal impending phishing campaigns.

By catching these events early, you get precious lead time to investigate and intervene before users are impacted. For instance, spotting a rogue subdomain insertion or a nameserver change within minutes can be the difference between silently neutralizing a threat versus discovering it only after customers report being phished. Security experts specifically recommend tracking domains that imitate your brand, like swapping letters or adding typos, and watching certificate transparency logs for lookalike registrations to catch such threats proactively. In practice, a strong monitoring solution will incorporate all these signals into high confidence alerts so that any suspicious DNS activity, whether internal or external, raises an immediate alarm for your team.

From Signal to Response

‍It is important to integrate DNS monitoring into your broader security operations and response plan. Detecting a suspicious DNS change is only step one; your team must then validate whether it is truly malicious or just a benign config change, contain the threat, and remediate any damage done. In many cases, this means kicking off your incident response playbook or enlisting your managed detection and response (MDR) team to quickly triage the indicator, evict any adversaries, and patch the weakness that allowed the issue. The advantage is clear: by having that early DNS signal, you are not starting from scratch when responding because you have a head start. As the saying goes, “Signal is step one. Response is execution.” An early warning from DNS buys you time to execute an effective response, whether that means updating credentials, restoring correct records, or notifying partners and users.

Conclusion

‍For security leaders at large organizations, the takeaway is that proactive DNS oversight is no longer optional. If industry giants can fall prey to DNS hijacks due to something as simple as a forgotten record or an impersonation domain, so can you. The good news is that gaining visibility into DNS is easier than ever. New solutions, including free ones, now offer automated DNS scanning and alerting to help teams catch these issues early. By establishing your baseline and monitoring for anomalies, you can transform DNS from a blind spot into an early warning system. That means fewer surprises, faster incident response, and ultimately a stronger shield around your users’ trust.

Ready to activate your DNS early warning system?

You can get started with Cantina’s free DNS Monitoring in minutes. It provides baseline scans to map your domain surface and real time alerts for any changes or abuses. The service even comes with a hands on onboarding for early teams, so you will be up and running with high signal alerts from day one. In a world where DNS is the new front line, this kind of proactive monitoring can make all the difference in staying ahead of threats.