DNS hijacking is a common and highly harmful attack method. It can cause users to be redirected to incorrect pages when accessing websites, potentially leaking sensitive information. With the development of the internet, both individual users and corporate websites are at risk of becoming victims of DNS hijacking. If issues are not promptly addressed, they can lead to a poor user experience, compromised data security, and even disrupt business operations.

　　Ⅰ. The Dangers and Common Manifestations of DNS Hijacking

　　DNS is the core mechanism of the domain name system. When a user enters a URL into a browser, DNS resolution is used to obtain the target server's IP address. If an attacker tampered with the DNS resolution process, this is known as "DNS hijacking." Common hijacking symptoms include:

1. Users are redirected to advertising or phishing websites when accessing a website.
2. The website may be operating normally, but some users report being unable to open it, indicating a resolution error.
3. When querying a domain name using the ping or nslookup command, the IP address returned is not the actual server address.
4. The website's SEO is damaged, as search engine crawlers may also be affected by the hijacking, resulting in abnormal indexing or reduced ranking.
5. Access to internal enterprise applications failed, causing business system outages.

　　From a threat perspective, DNS hijacking not only disrupts the user experience but can also lead to data leakage. Attackers can collect account numbers and passwords from fake pages, or even trick users into downloading malware. Therefore, remediation measures must be taken immediately upon detecting signs of hijacking.

　　Ⅱ. Quickly Confirm Whether You've Experienced DNS Hijacking

　　Before remediating, you must first confirm whether the issue is caused by DNS hijacking. Common detection methods include:

　　Using a local command line tool:

  nslookup www.example.com

　　Compare the returned IP address to the official server IP.

　　Test in different network environments, such as switching to a mobile hotspot or using a foreign DNS server, to see if access is successful.

　　Use an online DNS testing tool to check the resolution results for multiple regions. If you notice an unusual distribution of resolution results, this indicates hijacking.

　　Quick confirmation is crucial, as website inaccessibility may sometimes be due to server downtime or CDN misconfiguration, rather than DNS hijacking. Only after identifying the issue can targeted remediation measures be implemented.

　　Ⅲ. Temporary Solutions for Quickly Fixing DNS Hijacking

　　When a DNS hijack has occurred, businesses and individuals are most concerned about quickly restoring access. Here are several effective temporary solutions:

　　1. Switch your public DNS: Users can manually modify their network settings to use a stable public DNS. These DNS services are generally highly secure and can circumvent some hijacking attempts.

　　2. Modify the Hosts File: On a personal computer or server, you can modify the Hosts file to point a domain name directly to the target IP address, bypassing the DNS resolution process. However, this method is only suitable for a small number of users and is not suitable for large-scale implementation.

　　3. Use Encrypted DNS: Modern browsers support DoH (DNS over HTTPS) or DoT (DNS over TLS). These encryption protocols prevent local carriers or third parties from tampering with DNS resolution results and are suitable for individual users as a temporary safeguard.

　　4. Clearing the cache: The local DNS cache or browser cache may contain hijacked records. Clearing the cache promptly can prevent further access to the incorrect IP address. Command example:

  ipconfig /flushdns

　　While these methods can quickly resolve some issues, they are generally temporary measures and cannot fundamentally address the risk of DNS hijacking. In enterprise scenarios, more in-depth mitigation solutions are required.

　　IV. Fundamental Remediation Measures at the Enterprise Level

　　For corporate websites, if DNS hijacking is confirmed, user-side adjustments alone are insufficient. Fundamental remediation efforts are required across three areas: domain name resolution, server configuration, and network security:

　　1. Check the security of your domain name resolution provider: First, log in to your domain name registrar or DNS provider's backend to check if the domain name resolution records have been tampered with. If any anomalies are found, immediately restore the correct records and enable two-factor authentication to prevent further account theft. Choosing a provider that supports DNSSEC is also a long-term protection measure.

　　2. Deploy DNSSEC: DNSSEC uses cryptographic signatures to ensure the authenticity of resolution records, making it difficult for hackers to forge signatures even if they tamper with the resolution path. For important corporate websites, enabling DNSSEC can effectively reduce the risk of hijacking.

　　3. Use high-defense DNS or cloud resolution: Many cloud providers offer high-defense DNS services with intelligent scheduling and hijacking detection capabilities, automatically switching routes, and ensuring stable global access. For e-commerce, financial, and cross-border websites, these services are recommended.

　　4. Combined with CDN protection: If DNS hijacking causes access anomalies in certain regions, CDN intelligent scheduling can redirect traffic to unaffected nodes. CDNs can also hide the origin server IP address, reducing the risk of direct exposure.

　　5. Strengthen the security management of servers and domain name accounts: Many DNS hijacking cases stem from compromised domain management accounts. Therefore, companies should regularly change passwords, enable two-factor authentication, and restrict the range of administrative IP addresses.

　　Through these measures, companies can address the root causes of DNS hijacking and prevent recurrence.

　　DNS hijacking is a highly destructive and widespread form of cyberattack. To quickly fix such issues, individual users can temporarily resolve them by changing their DNS, clearing their cache, or enabling encrypted DNS. Corporate websites, however, need to address the root causes and completely eliminate the risk of hijacking through the use of DNSSEC, high-security DNS, CDN, and account security management. At the same time, long-term protection and monitoring mechanisms are also crucial for ensuring network security. For any business that relies on the internet, establishing a comprehensive security defense system in advance is far more efficient and cost-effective than repairing it afterward.