DNS Malicious Attack Protection Security Guide: Key Defense Tips to Share

in the digital office and daily network access, DNS, as the conversion hub of domain name and Internet Protocol Address, is the key entrance of network communication. However, with the escalation of network threats, DNS malicious attacks have become a common means of stealing data and hijacking traffic. Once caught, it may lead to serious consequences such as users jumping to phishing websites and core data leakage of enterprises. This article will sort out the protection skills of DNS malicious attacks for your system from multiple dimensions such as attack identification and defense means, and help you build a cyber security defense line.

How to identify common DNS malicious attacks?

want to effectively defend against DNS malicious attacks, we must first be able to accurately identify different types of attack characteristics in order to take targeted countermeasures.

1, DNS cache poisoning attack

this kind of DNS malicious attack will inject false domain name resolution records into the cache of the DNS server, and when the user visits the target domain name, it will be directed to the malicious site preset by the attacker. Its typical feature is that the Internet Protocol Address resolved by the same domain name at different end points or time periods is inconsistent, and the site pointed to by the resolution result has abnormal content such as phishing and malicious downloads.

2, DNS amplification reflection attack

the DNS malicious attack takes advantage of the amplification effect of the DNS server to send a request packet of forged source IP to the public DNS server, the server will send a large number of response data to the forged target IP, eventually leading to the target internet bandwidth being exhausted and service paralysis. The identification feature is that the target server receives a large number of response data packets from legitimate DNS servers in a short time, and the traffic far exceeds the daily normal level.

Deploy basic protection against DNS malicious attacks

the basic protection system is the first checkpoint against DNS malicious attacks, which can effectively intercept most conventional attacks.

1, configure a secure and reliable DNS server

prioritize public DNS servers that have been certified for security, or deploy internal dedicated DNS servers and timely update system patches, turn off unnecessary recursive query functions, and avoid becoming tools or targets for DNS malicious attacks. At the same time, it is necessary to regularly clean the DNS cache to prevent false resolution records from persisting for a long time.

2 Enable DNSSEC Domain Security Extensions

DNSSEC verify the authenticity and integrity of the domain name resolution record through digital signature technology, which can effectively prevent DNS malicious attacks such as DNS cache poisoning. After enabling this extension, the DNS server will sign the resolution record, and the user end point will verify the validity of the signature when receiving the resolution result. If the record is found to be tampered with, it will reject it.

3, block DNS malicious attacks through traffic monitoring

real-time monitoring of network traffic is the core means to detect and block DNS malicious attacks in a timely manner, and the risk can be controlled in the early stage of the attack.

1, build DNS traffic analysis system

deploy professional DNS traffic analysis tools to monitor DNS request and response data packets in real time, focusing on abnormal request frequency, response size and resolution record changes. When traffic that meets the characteristics of DNS malicious attacks is detected, the system can automatically trigger an alarm to remind administrators to intervene in time.

2, set traffic access control policy

in the network boundary firewall or intrusion detection system, set up access control rules for DNS traffic, limit the frequency of DNS requests for a single Internet Protocol Address, intercept abnormal recursive requests from unknown IP, and filter the resolution request containing malicious domain name characteristics.

4. Client protection reduces the risk of DNS malicious attacks

In addition to the server-side protection, the user-side security settings can also effectively reduce the probability of DNS malicious attacks, forming a full-link protection closed loop.

1, fixed trusted DNS server address

users manually configure the verified trusted DNS server address in the end point device to avoid automatically obtaining unreliable DNS resolution services and reduce the possibility of DNS malicious attacks. At the same time, regularly verify the accuracy of DNS resolution results, and replace the DNS server in time if any abnormalities are found.

2, install end point security software

install security software with DNS protection function on the end point device, such software can monitor the DNS resolution request in real time, intercept the resolution result pointing to the malicious site, and warn the phishing website and malicious download link, and resist the subsequent risk of DNS malicious attack from the user access end.

To sum up, the protection of DNS malicious attacks is a multi-dimensional and full-link system engineering, which needs to be coordinated from attack identification, server-side deployment, traffic monitoring to user-side settings. By accurately identifying attack characteristics, building a basic protection system, monitoring traffic abnormalities in real time, and strengthening user-side security settings, a solid line of defense against DNS malicious attacks can be effectively built to ensure the security and stability of network access.