How to detect DNS hijacking by operators? Practical self-examination and protection guide

in daily network use, many people have encountered the situation that web pages jump to unfamiliar sites, pop-up windows force advertisements, and commonly used websites cannot be opened normally, which is likely to be caused by DNS hijacking by operators. This hijacking behavior will not only interfere with the normal network access experience, but also may bring the risk of information leakage and malicious software implantation. This article will explain in detail the detection methods of DNS hijacking by operators, as well as corresponding protection measures, to help you quickly troubleshoot abnormalities and ensure the safety of network use.

What are the typical manifestations of DNS hijacking by operators?

to detect DNS hijacked by operators, it is first necessary to clarify its common abnormal characteristics, so as to detect the problem in time.

1, web page jump strange malicious site

enter the correct domain name of the commonly used website, but jump to completely unrelated unfamiliar pages, such as vulgar advertising websites, fake winning pages, etc., which is a typical manifestation of DNS being hijacked by operators. Under normal circumstances, the domain name will resolve to the server IP of the corresponding website, and the resolution result after hijacking is tampered with, there will be a jump abnormality.

2, frequent pop-up forced advertising

when visiting a regular website, pop-up advertisements that have nothing to do with the content of the website frequently pop up, even after closing the advertisements, they will still appear repeatedly, and even some advertisements cannot be closed normally. Such advertisements are often forcibly implanted in the parsing process after DNS is hijacked by operators, which seriously affects the browsing experience.

3, commonly used websites cannot be accessed normally

a well-known website that could have been opened normally, suddenly there is no access, slow loading or 404 error, but it can be opened normally after changing the network environment.

Practical detection methods for DNS hijacking by operators?

when the above abnormal performance occurs, you can confirm whether DNS is hijacked by operators through professional detection methods.

1, command line query analysis results

press the Win + R key in the Windows system and enter cmd to open the command prompt, enter the "nslookup domain name" command to view the returned Internet Protocol Address; open the end point in the Mac or Linux system and enter the "dig domain name" command. Compare the queried Internet Protocol Address with the official IP of the website. If the results are inconsistent, it can be determined that the DNS is hijacked by the operator.

2, replacement network environment comparison test

use mobile phone traffic or other operators to access the same domain name, if the website can be opened normally in other network environments, and there are no advertising pop-ups and jump abnormalities, and the original network environment is still the problem, then it can be determined that the current network DNS hijacked by operators.

3 Use online DNS resolution tools to detect

with the help of a third-party online DNS resolution query tool, after entering the domain name, obtain the resolution results of multiple regions and multiple DNS servers, and compare the resolution results of the current network. If the resolution results of the current network are significantly different from most normal results, it can be judged that DNS is hijacked by operators.

How to effectively protect DNS after being hijacked by operators?

once it is confirmed that DNS is hijacked by operators, it is necessary to take corresponding protective measures to restore normal network access environment.

1 Replacing public DNS servers

give up using the operator's default DNS server and replace it with a nationally or internationally renowned public DNS, such as Alibaba Cloud public DNS, Tencent public DNS, Google public DNS, etc. These public DNS servers are more secure and not easy to be hijacked, which can effectively avoid the problems caused by DNS hijacking by operators. The replacement method is also very simple. In the network settings of the computer or router, find the DNS server address option and enter the corresponding public DNS address.

2, turn on the router DNS protection function

most home routers have DNS protection or DNS hijacking interception function, enter the router management background, find the corresponding security settings options, and turn on the DNS protection function. Some high-end routers also support custom DNS filtering rules to further enhance the protection ability and prevent DNS from being hijacked by operators from the source.

3, use HTTPS encryption to access websites

try to choose a website that supports HTTPS encryption protocol to visit. The HTTPS protocol encrypts the domain name resolution and data transmission process, which can effectively prevent data tampering after DNS is hijacked by operators. Now most regular websites support HTTPS access. You can manually add the https://prefix when entering the domain name, or turn on forced HTTPS access in the browser settings.

IV. Emergency treatment steps after DNS is hijacked by operators?

if the DNS has been hijacked by operators, in addition to long-term protection, emergency measures need to be taken to quickly restore normal network use.

1, clear browser cache and Cookie

part of the DNS is hijacked by the operator after the implantation of advertising or jump information will be stored in the browser cache, clear the browser cache files and cookie data, can temporarily solve some pop-up advertising problems, to avoid abnormal data browser loading cache.

2, contact the operator feedback problem

to the operator's customer service feedback DNS hijacked by operators, provide specific abnormal performance and detection results, require operators to troubleshoot and repair DNS resolution abnormalities. Some operators will quickly adjust the resolution configuration after verifying the problem and restore normal DNS services.

To sum up, DNS hijacking by operators will bring many troubles and risks to network use. By identifying typical performance and using professional detection methods, abnormalities can be quickly checked. Once it is confirmed that it has been hijacked, it can be protected by changing public DNS, turning on router protection, and using HTTPS encrypted access. At the same time, cooperate with emergency treatment measures to restore the normal network environment. When using the network daily, pay more attention to access abnormalities and take timely measures to ensure cyber security.