ACSIA Help Center

What is a “DNS firewall block”?

Permanently deleted user
Permanently deleted user
  • Updated


This article will explain the ACSIA alert called "DNS Firewall block".

Explaining the DNS Firewall block

"DNS firewall block" refers to a protective measure that stops an unauthorized or potentially harmful connection attempt before it reaches the intended target system or network. This security mechanism acts as a barrier at the domain name system (DNS) level, preventing malicious traffic from reaching its destination and ensuring that the system remains protected from various cyber threats.

Example of a "DNS firewall block" attack:

Imagine a medium-sized organization with a well-secured internal network. The organization's IT team has implemented a DNS firewall to protect against various cyber threats, including malware and phishing attempts.

An attacker outside the organization attempts to launch a specific type of attack called a "command-and-control" (C&C) attack. In this attack, the attacker aims to establish communication between their malicious software (such as a botnet) and compromised devices within the organization's network.

The attacker's malware is programmed to communicate with its command-and-control server by sending and receiving specific signals using domain names. However, the organization's DNS firewall recognizes the malicious domain name or suspicious patterns in the DNS requests made by the attacker's malware.

As soon as the attacker's malware attempts to make a DNS request to reach the command-and-control server, the DNS firewall springs into action. It detects the malicious activity and immediately blocks the connection attempt. By doing so, the DNS firewall prevents the attacker's malware from establishing communication with the command-and-control server, effectively neutralizing the threat.

In this example, the "DNS FIREWALL BLOCK" plays a crucial role in defending the organization's network from a command-and-control attack. It ensures that malicious traffic is intercepted and stopped at the DNS level, before it can cause any harm or compromise the organization's devices or sensitive data. 

ACSIA alerts you when a DNS firewall block attack is performed on your infrastructure.

Related to