A DNS attack already sounds as dangerous for your online business. But it gets worse because there are different and already popular DNS attack types. Knowing them, you can choose the best protection!
DNS flood attack
This is exactly the technique used by the unfortunately popular DoS and DDoS attacks. The target is a DNS server (or more servers). The objective is to overload it with traffic until the point it can’t answer DNS requests anymore. Once the DNS fails, the denial of service will occur. When the attack comes from a single source (IP address), it can be easier to mitigate. But when thousands or more IP addresses get involved in the attack, mitigation is very challenging.
This is the type of DNS attack in which DNS requests are resolved but not in a correct way with the clear objective of redirecting users to malicious websites. Usually, a DNS server gets hijacked and controlled by a criminal. Some of the DNS records are changed, pointing to a fake site controlled by the criminal. Then, all legit queries go to the dangerous site.
Attackers can accomplish their criminal objective by taking over routers, hacking DNS communication, or installing malware on user devices.
DDoS amplification attack
There are several ways to execute it, but generally, it exploits a vulnerability of the User Datagram Protocol (UDP). UDP doesn’t use verification. Attackers send little DNS requests, but they ask for much more information than only a single DNS record. Therefore, the answer can be very large. In addition, criminals can change the request for the answer to go to the victim. As a result, the victim gets a huge number of DNS answers it didn’t ask for. Then, the downtime and denial of service for users take place.
This attack has the objective of stealing key information from a victim via DNS, evading detection. What they do is create a tunnel by sending small pieces of infected code. They look like normal DNS requests but are a cover for sending hidden and malicious data. Then, when the tunnel is ready, criminals can steal your business information. You won’t notice what’s happening because the tunnel is an effective protection for criminals.
The NXDOMAIN attack’s objective is to disrupt a DNS server’s normal functioning and availability. Criminals send a flood of DNS requests to their victim (DNS server) for it to resolve a non-existent domain name. The DNS server will take those requests as valid, so it will try to resolve the domain, but it won’t find it because the records are invalid or non-existent.
The DNS server’s cache will get full of NXDOMAIN answers. The response time for valid requests will be sluggish. Then the server will shut down.
This list of popular DNS attack types is scary enough to protect your online business right now! Prevention is essential! Remember that cybercrime does not sleep.