Antiviruses are essential if you use Windows as your operating system. Microsoft Defender is included, and offers the best possible protection at the level of paid antivirus. However, there are antivirus that offer functionalities that others do not have, so, is it possible to have two installed ?
Having two antivirus installed on a computer may sound like a great idea on paper. For starters, we have additional functionalities that someone else cannot have, such as a built-in VPN, or even an option to safely mine cryptocurrencies directly from the program without installing suspicious software. In turn, we can protect ourselves from more vulnerabilities and malware by having two databases instead of one.
The answer to the first question is simple: yes, it is possible to run two antivirus programs at the same time on one computer. These antivirus must be different from Defender, since when we install a third-party antivirus, Defender is automatically deactivated. However, the fact that we can does not imply that we should.
To begin with, an antivirus is a program that gets to access the most sensitive parts of the operating system, such as the kernel , in charge of communications between the software and the hardware. Thanks to this, it can identify any type of threat and end it.
Most of today’s antivirus have real-time scanning systems. When we open a program, visit a website, or download a file, these antivirus scan everything for malicious content to neutralize it before it can run on our computer.
Fight between antivirus
Therefore, if we have two antivirus running at the same time, both will fight to end the threat. When doing so, two things can happen: one of the antivirus is late to neutralize the threat and fails because the other has already neutralized it. The second is worse: that, when trying to neutralize it, it generates a crash in the computer.
The antivirus runs with the highest privileges on the system , and it knows perfectly the paths that the malware follows when it runs. With these permissions, you can modify any suspicious data or code, and save it in a safe place so that the user can decide later whether to delete it or not.
Thus, the antivirus does practically the same thing that a malware would do, and this behavior can be seen by another antivirus as dangerous. And in turn, the antivirus can identify this behavior as an attack. In that way, it is like leaving two smart speakers interacting with each other infinitely, and it can cause the computer to crash, or a virus to sneak into the computer while the two antiviruses are fighting .
Another possible problem that may arise is that, while an antivirus is blocking a virus, the second antivirus detects that blocking as malicious behavior and decides to block it. Even if they detect a file as a false positive and quarantine it, it can be difficult for you to recover it if both antiviruses apply protection measures to it.
Slower computer
Another disadvantage of having two antivirus is that the computer becomes slower . Having an antivirus on your computer already slows down some things on your computer, such as opening programs or downloading files before you can run them. The CPU consumption can be high from time to time, and with two antivirus programs that is even more noticeable. In a laptop, the battery can be seriously affected.
What to do if you want a “second opinion”
If you have downloaded a file that the file has marked as malware, and you do not trust that it is right, installing a second antivirus is not the solution . The most comfortable thing in these cases is to upload the file or the link from where we have downloaded it to websites such as VirusTotal. There, the file is analyzed by more than 50 different antivirus . If you don’t trust analyzing it on your main computer, you can always do it on a secondary computer or in a virtual machine.
In case you want to do it with two antivirus, you can have the secondary one deactivated . When you want to analyze a file, you deactivate the main one and activate the secondary one, thus ensuring that they do not conflict. However, there may be other mechanisms in the background
In short, not only is it not necessary to have two antivirus installed, but you should avoid it at all costs. It is important to have some of the best antivirus that has the most complete database possible, and the vast majority of them usually have it, such as Defender, Norton, Avast, Kaspersky or Bitdefender . All antivirus are constantly updated with the new threats that they detect on the network, which helps a lot to reduce their reach.