Causes and signs to identify a computer infected with Virus

In the process of using the computer, if you are not careful or just a small mistake, your computer is very susceptible to virus infection.

So how to know if your computer is infected with a virus or not and why? In this article, we will learn more about the Virus and how to prevent it.

1. What is a computer virus?

First, I will talk about the concept of a virus, you can simply understand that a virus is a very small piece of software and it has the ability to replicate and copy itself from one infectious file to another. And of course viruses have many types from simple to complex, sometimes just a short piece of code, it is often created with bad purposes.

Viruses develop very strongly in the Windows operating system, not because this operating system is weak in security, but because it is so popular that many 'masters' watch and write malicious software to deceive. users for their own benefit.

2. Where does the virus come from?

Viruses can spread through computers from many different sources. It can be spread through the Internet, spread through the Lan network, spread from peripheral devices…. And I will list some specific cases below:

1. Spread via USB, memory cards, CD drives.or other removable devices. This case is quite common (you should read the article on how to prevent viruses from spreading from usb).
2. Spread by email, email services or downloaded files on the internet.
3. Do copy and use files that have been infected with viruses before.
4. Due to users accessing unhealthy websites.
5. By clicking on links containing viruses on the internet, virus files are attached to images.
6. Using pirated, non-copyrighted software from unreliable sources, do not test carefully before using.
7. Infected via LAN, intranet.
8. Being infected with a virus because the software installed on the computer is infected with a security hole.

=>> Viruses are getting smarter, or more precisely, the creators of the virus are getting better and more sophisticated, so users will be more easily fooled.

3. How do viruses work?

The file is infected with a virus => after it is activated (unintentionally activated by the user) => starts working and permanently resides on the infected file => continues to find another object to infect.

This process will repeat until all files are infected with viruses if you do not have a prevention method.

4. Harm when the computer is infected with a virus

Viruses cause a series of serious problems for us, they can slow down computers, consume resources, corrupt Windows, lose data, steal data, blackmail users such as Ransomware WannaCry . . and many other harmful effects inhibiting the user.

5. Signs to identify a computer infected with a virus?

1. The computer starts up slowly, freezes, jerks and lags more than usual.
2. The computer automatically starts or shuts down for no apparent reason.
3. Anti-virus software or firewalls are suddenly disabled and unusable.
4. Unable to start programs or applications on the computer.
5. The drive, folder or print job cannot be used on the computer.
6. Icons on Desktop are lost or changed.
7. Retrieving, opening files or opening program files is slow.
8. Strange files appear when opening the USB hard drive.
9. Suddenly appeared files with the .exe extension with the same name as the folders.
10. A yellow triangle warning appears in the right corner of the 'Your computer is infected' screen, or the 'Virus Alert' window appears.
11. Appears advertising websites that automatically appear (pop up).
12. When opening a web browser, it automatically opens strange website popup windows.
13. Internet access speed is very slow, although the network is still normal.
14. The Desktop screen is changed even though you do nothing.
15. Unable to use system tools such as Task Manage or Registry Editor (Press Ctrl + Alt + Del to open Task Manager, CPU and RAM are always high, even 100%.)
16. Many strange programs, software or tools run on their own at startup.
17. Appears many strange icons that you have never installed.
18. The web browser that you still use regularly has its homepage changed automatically and cannot be reset.
19. Folder Option function is locked.
20. Folder Icons Return to Ancient Windows XP Icons