signs of a computer virus

All the signs of a computer virus

So, your wondering if your computer might have been infected with a virus? Well there are many different signs of a computer virus, and today I’m going to go over a few of the most common ones. but first lets talk about viruses in general and how they operate.

what is a computer virus?

A computer virus is malicious software written with the intent to harm you or your computer, and/or steal personal information. Therefore the primary objective of most computer viruses is to, 1 infiltrate your computer, and 2 spread as much as it can. And there are many different types of viruses, for instance.

Boot Sector Viruses

– one of the most notorious types of viruses. As it attaches to the master boot record on your HDD allowing full control of your system, hardware/software. Boot sector viruses are some of the most tricky to remove and often require a full HDD wipe for removal.

Since the boot sector virus is run during the boot phase of the computer and before the antivirus is run there is no way of detecting and/or removing through anti-virus software, in most cases.

File Infector viruses

– The most common type of computer virus that infects executable programs “software with the .exe or .com file extension”. This kind of virus attaches to software on your computer or downloaded from the internet, and is activated when the infected software is run “direct action”.

Most common File Infector viruses can be removed by anti-virus and/or virus removal tools depending on the severity of the virus.

Resident Virus

– Another type of File Infector virus that is not direct action. This particular virus installs a copy of itself on the system so it can be run at anytime compared to only when the infected software is run as is the case with direct action File Infector viruses.

Resident Viruses are more dangerous in the sense that they can run with out you even being on your computer. And like File Infector viruses Resident Viruses can be removed with anti-virus software or virus removal tools in most cases.

Multipartite Viruses

– Whereas most computer virus focusing on one infection and spreading that infection, Multipartite Viruses go for multiple infections and spreading all of them. Therefore a virus of this caliber has the capability of infecting both your master boot record “boot sector virus” and software on the machine “File Infector viruses”.

Muttipartite Viruses can be really time consuming and tedious to remove. In extreme cases a full HDD wipe is required depending on the number of infections and damage done to the system.

Hidden Viruses

With all the different types of viruses on the internet, it can sometimes be impossible to see the signs of a virus. Because with some viruses there simply are no signs. For instance, there are certain File Infector viruses that have the primary purpose of doing nothing but maximizing the spread of the virus. In this instance, the virus does not show any signs of slowing the computer in its beginning stages.

While other computer viruses will remain dormant on your system until a certain day or time. Such as the famous Michelangelo virus of 1992.

These types of viruses can also wait for a certain trigger to activate it. As in opening a specific file, typing a certain phrase, or even a remote activation.

Just because the virus remains dormant or hides from user suspicion does not mean it cannot be detected by anti-virus software. That being said you should always make sure you have proper anti-virus/fire-wall software installed and updated. Make sure to do regularly scans with your anti-virus software and you can be sure to not have any dormant virus lurking on your system.

Signs of a Computer Virus

The more common Direct Action virus will start to show certain symptoms right away. These signs of a virus can be detected by the user almost immediately.


Signs of a virus BSOD
Blue Screen of Death


Computer Slowing

Is the most common symptom of a virus.

Gradual Computer slowing is normal with all computers over time. As the HDD gets filled with more and more applications and documents that system might start to slow. But if your system experiences a rapid decrease in speed, and it keeps getting worse, than your computer most likely has a virus.

In the instance where a users computer is working fine one day, but the next day has slowed to a crawl. That user can be 90% sure that a virus has infected the machine.

Computer Crashes

If your computer is crashing frequently, “restarting every ten minutes” freezing constantly while trying to navigate the desktop. Or is showing the dreaded BSOD “Blue Screen Of Death”. Then your machine is infected with a computer virus.

Another sign would be your screen constantly going black for a few seconds then returning to normal. Or the flickering screen, these are all signs of a computer virus.

Pop Ups

In all instances, pop-ups are always a sign of a computer virus and/or spyware. If every time you start your computer your riddled with ads telling you to buy this or upgrade that. Slowing down your everyday computer use and popping up every few minutes. Then you have a virus and/or spyware that needs to be removed.

Slow Booting Computer

If the PC starts up and hangs during the boot phase or freezes completely. Or if the computer locks you out of your system, asking for a password that you didn’t set, before The OS even starts. Then this is a common sign of a boot sector virus and should be cleaned immediately.


In the event your computer locks you out of a specific program or user account it might be infected with Ransomware. This type of virus will then try to collect payment from you in return for your locked out program or account.

Ransomware viruses can always be removed and should never be paid the ransom that it is asking for. As once the virus has control of your system it will never give it back. Only make you think that it did.


This type of virus also falls in the same category as pop ups. As it riddles your computer with pop ups telling you that your computer has been infected with hundreds of viruses. The virus will then tell you in order to clean the infections you have to call this number or go to this website. Once you call the number or go to the website specified the virus will then try to charge to get your system back to normal.

As in the case with Ransomeware, once the virus has control of your system it will never give it back. Only make you think that it did.

In this instance you should never attempt to do what the virus is asking. Instead a full system wipe and/or data Backup/Recovery should be performed. This will make sure there are no traces of the virus hiding on your system.

Thank you for reading, Those are the most common signs of a computer virus. If experiencing any of the stated issues “or any computer related issue” feel free to contact me directly on my about page with any computer related issue in the Colorado Springs, Colorado area.

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