DNS hijacking is a silent but dangerous cyber threat that redirects your internet traffic without your consent. Instead of reaching the websites you intend to visit, you’re secretly pointed to malicious clones, ad-filled pages, or surveillance endpoints.
This manipulation happens at the DNS (Domain Name System) level — the service responsible for translating domain names into IP addresses. It can be triggered by malware, rogue routers, or even your internet provider. The result? Stolen credentials, injected malware, and constant surveillance.
This article will help you understand how DNS hijacking works, how to detect it, and how to protect yourself using tools like Control D.
How Does A DNS Hijacking Attack Work?
DNS hijacking works by intercepting or altering the DNS resolution process, the part of your internet connection that figures out where a website physically lives on the internet.
Normally, when you type a URL like controld.com, your device asks a DNS resolver, “What’s the IP address of this site?” The resolver then returns the correct address, and your browser connects to the server. But if a hijacker gets in the middle, by infecting your router, tampering with your device, or spoofing your DNS settings, they can change that answer.
Instead of returning the real IP address, the rogue resolver replies with an IP of their choosing. That could be:
- A phishing page that mimics the real site
- A malware server that delivers infections
- An ad-heavy landing page that generates revenue per impression
- A "blocked" page that’s actually state-level censorship
Hijackers may gain access through:
- Malware on your device
- Insecure public Wi-Fi networks
- Compromised routers (especially those using default credentials)
- DNS servers under an ISP or nation-state's control
Because the DNS query happens before encryption, hijacking it is often invisible to users.
How Can You Detect DNS Hijacking?
Detecting DNS hijacking isn’t always straightforward, but there are several signs and tools that can help you uncover foul play.
1. Unexpected HTTPS Warnings
If your browser warns you about a certificate mismatch on a trusted site (like Gmail or Amazon), the DNS may be sending you somewhere fake.
2. Wrong IP Address
Use nslookup or dig in your terminal to manually check the IP for a known domain. You may be hijacked if the result doesn’t match what other trusted DNS resolvers return (like Control D).
3. DNS Leak Tests
Sites like dnsleaktest.com show you which servers are resolving your queries. If you see unexpected IPs or ISP-branded resolvers, that's suspicious.
4. Slowdowns or Ad Injection
Seeing random ads on normally ad-free sites? That’s a red flag. Hijackers often monetize their access by injecting ads into redirected traffic.
5. Check Your Router
Log into your router’s admin panel and inspect the DNS fields. If they're pointing to IPs you don’t recognize, change them and update the admin password immediately.
DNS Hijacking Examples
Here are some examples of DNS hijacking, some of which consist of the biggest DNS attacks in history.
- Turkish Government Hijack (2014): Citizens trying to access Twitter and YouTube during political protests were redirected to government-controlled servers. The DNS entries were manipulated at the ISP level.
- Comcast & Verizon Redirects: These ISPs were caught redirecting mistyped or nonexistent domains to ad-laden search pages rather than returning standard NXDOMAIN (non-existent domain) errors.
- Rombertik Malware: This spyware modified DNS settings on infected Windows PCs to redirect victims to malicious update servers, installing more malware.
- Public Wi-Fi Redirection: Many fake or rogue Wi-Fi hotspots in airports and cafes route DNS through malicious servers, showing fake login portals that capture credentials.
- Router Malware Campaigns: Malware like DNSChanger infected millions of routers worldwide, altering DNS settings to steal banking credentials and redirect users to scam pages.
DNS Hijacking vs DNS Spoofing vs DNS Cache Poisoning
Although often used interchangeably, DNS hijacking, DNS spoofing, and DNS cache poisoning refer to different attack vectors within the DNS ecosystem — each with its own method and impact.
DNS hijacking occurs when an attacker, or your ISP in some cases, forcibly redirects your DNS queries to a different DNS server than the one you intended to use. This can be done by altering your device’s settings, compromising your router, or rerouting traffic at the network level.
DNS spoofing, on the other hand, happens during the actual resolution process. It involves forging a fake DNS response to a legitimate query. Instead of your resolver returning the correct IP for a website, the attacker responds faster with a malicious one, often tricking your browser into connecting to a lookalike phishing site.
DNS cache poisoning takes a broader approach. Instead of targeting a single user, it aims to corrupt the cache of a recursive DNS resolver — the kind used by thousands or millions of users. By injecting false DNS records into the cache, attackers can misdirect traffic from many people at once until the poisoned record expires.
How to Protect Against DNS Hijacking
1. Use Encrypted DNS (DoH/DoT)
This prevents middlemen (like ISPs or malicious hotspots) from seeing or modifying your DNS queries. Enable DNS-over-HTTPS (DoH) or DNS-over-TLS (DoT) in your browser, operating system, or router.
2. Choose a Secure DNS Provider
Avoid using your ISP’s default DNS. Instead, pick a privacy-focused resolver:
- Control D: Encrypted DNS, customizable filters, detailed analytics
- Cloudflare: Fast, no logging
- Quad9: Blocks malware domains
3. Lock Down Your Router
- Change the default admin password
- Disable remote access
- Keep firmware updated
- Hard-code your DNS servers
4. Use a VPN with Private DNS
VPN services like Windscribe tunnel your DNS traffic through private resolvers, adding encryption and shielding queries from local manipulation.
5. Monitor Your DNS Logs
Use a resolver that gives you insight into what domains you’re querying.
How Control D Guards Against DNS Hijacking
Control D is purpose-built to neutralize DNS-level threats — hijacking included.
- Encrypted Protocols: All endpoints support DNS-over-HTTPS (DoH), DNS-over-TLS (DoT), and DNS-over-QUIC (DoQ), which prevents middlemen from seeing or modifying your queries.
- Custom DNS Routing: You can override ISP DNS entirely — even on routers — with Control D’s anycast network, which assigns you dedicated resolvers and keeps your traffic consistent.
- Profile Locking: Even if someone gets on your network, profiles can be locked to prevent unauthorized changes to DNS settings or filter rules.
- Realtime Logs & Domain Test: Control D gives per-device analytics. If a request gets hijacked, you’ll see exactly which domain failed or resolved unexpectedly, including the filter that blocked it.
- No Ads, No Logs: Control D doesn't sell or monetize your DNS data. No upstream manipulation. No shady redirection.
- Router & Device Setup Tools: Easy installers and setup utilities help you hard-code Control D across your devices and network — no DNS leaks, no fallback to ISP defaults.
