What is DNS anti-hijacking? Comprehensive explanation of principles and protection methods

in daily network visits, have you ever encountered a situation where you enter the correct URL but jump to an unfamiliar advertising page, or a commonly used website suddenly cannot be opened normally? This is likely to encounter DNS hijacking. In order to help you recognize this type of network threat, this article will explain from multiple dimensions such as the basic cognition, technical principles, and practical protection methods of DNS anti-hijacking, so that you can fully grasp the core knowledge of avoiding such risks and build a strong line of defense for network access security.

What is the basic understanding of DNS anti-hijacking?

to do a good job of DNS anti-hijacking, we must first clarify its protection object and core value, and first dismantle it from the basic concept.

1, the definition and harm of DNS hijacking

DNS is the Domain Name System, which is responsible for converting easy-to-remember domain names into Internet Protocol Addresses that computers can recognize, while DNS hijacking is a network attack method for attackers to access fake servers by tampering with DNS resolution results. Its harm is diverse, not only will it force the placement of advertisements to affect the browsing experience, but it may also guide users to phishing websites, resulting in the leakage of account passwords, property information, etc., and even the implantation of malicious programs to control user devices.

2, the core goal of DNS anti-hijacking

The core goal of

DNS anti-hijacking is to ensure the authenticity and integrity of the DNS resolution process, and to ensure that users can accurately access the corresponding regular servers after entering the domain name. Through various technical and management means, the path of attackers tampering with the resolution results is blocked, and users are prevented from encountering security risks such as domain name jump and information leakage from the root cause.

The core implementation principle of DNS anti-hijacking?

understand the principle of DNS anti-hijacking, it can help us understand the function logic of various protection means more clearly, and understand its protection essence from the technical level.

1, parsing protection

based on encryption verification

this is one of the core technical directions of DNS anti-hijacking. By adding a cryptographic verification mechanism to the DNS request and response process, the parsed data cannot be tampered with by attackers. For example, DNS over HTTPS and DNS over TLS protocols encapsulate DNS query data in an encrypted channel for transmission, and attackers cannot intercept or modify the parsing content to ensure the accuracy of the parsing results. At the same time, some DNS anti-hijacking solutions will add digital signatures, and the receiving end can confirm whether the parsing results have been tampered with by verifying the signature.

2, Analytic protection

based on path control

this kind of DNS anti-hijacking principle is mainly to reduce the possibility of being tampered by attackers by controlling the transmission path of the resolution request. For example, using a local DNS cache server, the user's resolution request is first processed by the local trusted server to avoid direct exposure to the public network; some enterprises will build a dedicated DNS resolution channel, so that the internal user's resolution request is only transmitted in the trusted network, blocking the intervention of external attackers from the path level.

Third, the commonly used DNS anti-hijacking practical protection methods?

mastered the principle, then look at the DNS anti-hijacking protection method that can be directly landed, covering different scenarios of individuals and enterprises.

1, replace the trusted public DNS server

for individual users, replacing the trusted public DNS server is the most convenient DNS anti-hijacking means. The common ones in China are Alibaba Cloud public DNS, Tencent public DNS, and Google 8.8.8.8 internationally. Such servers have perfect protection mechanisms and can effectively resist common DNS hijacking attacks. When replacing, just modify the DNS server address to the corresponding trusted address in the network settings of the device.

2, open DNS encryption and resolution function

most mainstream browsers and operating systems now support DNS over HTTPS or DNS over TLS functions. After opening, DNS resolution requests can be transmitted in encrypted channels, which is also an efficient way to prevent DNS hijacking. Take Chrome browser as an example, you can find the privacy and security option in the settings, turn on the secure DNS function and select a trusted encrypted DNS service provider to block the possibility of attackers tampering with the resolution results from the transmission level.

3, enterprises build a dedicated DNS system

For enterprise users, building an internal dedicated DNS system is a more secure DNS anti-hijacking solution. By deploying your own DNS server, you can control the resolution requests of all internal end points, and configure the DNSSEC digital signature verification mechanism to ensure the authenticity of the resolution results. In addition, you can also combine firewalls and intrusion detection systems to monitor DNS requests in real time and intercept abnormal resolution behaviors in time.

4, DNS anti-hijacking daily detection and operation and maintenance points?

DNS anti-hijacking is not once and for all, daily detection and operation and maintenance can continue to protect the protection effect and avoid protection loopholes.

1, regularly check DNS resolution results

users can regularly check the resolution results of commonly used domain names through command line tools or online DNS query platforms, and compare whether the official Internet Protocol Address is consistent to determine whether DNS hijacking has occurred. For example, use the nslookup command in the Windows system, use the dig command in the Linux system, and enter the domain name to view the returned Internet Protocol Address. If there is an unfamiliar IP, there may be a risk. It is necessary to check whether the DNS anti-hijacking measures are invalid in time.

2, timely update protection system version

whether it is the operating system of personal devices, browsers, or corporate DNS servers, firewalls, must be timely updated to the latest version. Attackers will continue to dig new system vulnerabilities to implement DNS hijacking, and official version updates often fix known vulnerabilities and strengthen DNS anti-hijacking capabilities. At the same time, it is necessary to regularly check the DNS anti-hijacking configuration to ensure that encryption, analysis, signature verification and other functions are enabled normally.

To sum up, DNS anti-hijacking is a key link to ensure the security of network access, from basic cognition, technical principles to practical methods, each link is closely related. Individual users can do a good job of protection by replacing trusted DNS and opening encryption and resolution, and enterprise users can build a dedicated DNS system to strengthen control. At the same time, with daily detection and version update, you can effectively resist DNS hijacking threats and build a reliable security barrier for network access.