What type of attack does DNS exfiltration refer to?

DNS exfiltration refers to the method of transferring data out of a secure network using the Domain Name System (DNS) protocol. This technique takes advantage of DNS queries and responses, which are typically allowed through firewalls and network security measures, to send data or files to an external server without raising suspicion.

Utilizing DNS for tunneling allows attackers to encode data within legitimate DNS requests, disguising exfiltration as normal DNS traffic. This method can be effective because many organizations may not closely monitor DNS traffic, making it an attractive avenue for data theft. By using DNS tunneling, malicious actors can bypass traditional security controls that are designed to prevent unauthorized data transmissions.

In contrast, the other options represent different types of cyber attacks. Direct hacking of servers involves exploiting vulnerabilities in server software or hardware. Phishing refers to attempts to trick users into revealing sensitive information, typically through deceptive emails or websites. A denial of service attack is aimed at making a service unavailable by overwhelming it with traffic. Each of these methods differs fundamentally from DNS exfiltration in their objectives and techniques used.