The security company F-Secure has launched an online application that allows you to quickly perform a DNS resolution test, it is called Router Checker and it is very easy to use, just enter and press the button. Start now.
In this way, it can be verified if the DNS of our computer and / or router are responding appropriately. DNS (Domain Name System) is something that we use every day when browsing the internet, thanks to them it is possible to transform IP addresses into domain names which are easier to remember than a series of numbers that even often often change .
A common practice of attackers is to modify the resolution of the DNS, something known as DNS hijacking, this way they can send you to false pages without you knowing it to show you unwanted advertising, infect you with downloads, block pages and request information from you through the phishing.
In your browser you may not notice it because in the address bar you will see the real domain of the site you want to access, but since the DNS resolution is compromised, instead of associating that domain with the legitimate server, you end up accessing a page that is on a server controlled by criminals.
I made this outline to show it a little more graphically:
DNS hijacking can be done directly on your computer, which could be quite serious because you probably have some other component of the malware operating. And they can also do it at the level of the routers, so they can end up affecting all the devices that connect to that network and go unnoticed for much longer since conventional antivirus does not check if the router is infected, although there are several that they perform a test in DNS like the one in this online tool. To mention one that is free, Avast does it.
And routers, believe it or not, can become infected through vulnerabilities in the software that controls them, called firmware. It has already happened on several occasions like this case that I mentioned some time ago where more than 4 million users had their router compromised without knowing it.
Someone who connects to the router's network and accesses its configuration panel could also put malicious DNS, something that in fact I have seen in hotels where they usually leave the default passwords or never update the firmware (see how to detect vulnerabilities in routers). ).
This tool that F-Secure has released is part of a campaign to promote other security solutions that they offer, but it is useful to perform a quick test of DNS. If a green icon appears and the message No Issues Were Found be all good.