Like the human body, computers can get sick or be infected by computer viruses that affect computer performance or that can access confidential information.
Surely you have heard a lot about computer viruses and the risk you run of being infected by some bad practice or simply by carelessness when browsing the Internet, opening files from unknown sources or clicking on certain links.
But, did you know that there are several types of viruses that can enter your computer? How do these types of threats work and what can you do to protect yourself? In this article we will tell you.
What is a computer virus?
A computer virus is a malicious program (malware) or code that affects the normal functioning of the computer without the user having authorized it. Like the flu, for example, computer viruses can spread from one computer to another quickly.
There are viruses that can endanger the computer they have infected, delete files and steal data. Although there are also other less dangerous ones that have only been programmed to cause annoyance to users of privacyonline.
Generally, computer viruses are housed in a program or file and when the user opens it, malicious code is executed and causes damage to the computer.
In the case of computers connected to a network, it is enough for the virus to run on one of the computers so that all those belonging to it are infected.
Types of computer viruses
Next, we describe the most common types of viruses that can affect your computer.
Boot sector virus
These are viruses that infect partitions of the computer’s hard drive. They are transmitted especially through removable drives such as USB sticks or external hard drives or Firefox VPN Extension. They do not infect files on the computer but rather the drive itself.
However, these viruses are rare today because most antivirus prevent them from reaching the boot sector and if they do, they are easily removed.
Macro virus
Are the most common computer viruses as frequently spread in Microsoft Word documents and spreadsheets of Exec l include macros or sequences of commands that run after pressing a button.
When an infected document is opened, the virus spreads and contaminates other files of the same type by changing their content.
File virus
They are found in executable files with .exe and .com extensions, which are generally downloaded from the internet.
The user, not knowing that the file is contaminated, executes it and in this way the virus affects other programs.
The goal is to compromise data and files, rewrite executable files, and even disable the computer’s security system.
Browser hijackers
The function of these viruses is to take control of the Internet browser.
To do this, they show the user pop-up windows or redirect them to web pages that they have not opened, showing the user advertisements that they must click on.
In general, they do not want to cause great damage to the computer or steal information, but rather to gain clicks so that the creator receives some monetary gain.
Scripting virus
Some web pages have been infected by hackers, usually by writing a comment masking the malicious code in the form of links.
Like browser hijackers, its creator wants to make money by forcing the user to watch text or video ads. However, there are cases in which they seek to steal cookies and / or steal user data to publish information on the Internet in their name.
A more popular classification divides viruses into these types:
Trojans
They can take over information or cause changes in hardware operation. In other cases they make it possible for an external user to take control of the computer. They are activated by opening a program associated with the virus.
Worms
They are viruses that can replicate themselves. They tend to take up memory and slow down your computer but don’t stick to other executable files.
Logic bombs or time bombs
They are executed when a certain condition is met or on a certain day and time. Until then, the virus remains in the system but inactive.
Polymorphic
These viruses are compiled by changing their internal structure, and compiled again, so that once a virus specimen is created again, it is different from the original.
Hoax and Joke
They are not properly a virus because they do not contaminate files or replicate themselves, but they do spread quickly.
Hoaxes are email messages or social networks that invite the user to share it on a chain.
While the Joke are annoying windows that appear in the internet browser and that cannot be closed.
How a virus works
The virus infection process begins when the user downloads a program or file to a computer. Understanding this download not only how to download it from the Internet but even copy it through a USB memory.
The user is unaware that the program or file is infected, so he opens or runs it.
At that moment, the malicious code is installed in the RAM memory of the computer and takes control of some aspects of the operation of the operating system and infects the files that are open.
Later, when these files are saved, the virus is transferred to the hard disk, thus completing the replication process.
There are other cases in which viruses are in the system but inactive, waiting for some condition to be met. When this happens, the virus runs and performs the process that we mentioned in the previous paragraphs.
Infection methods
How can a computer be infected by a virus? How do viruses spread? The most common methods of infection are these:
- Through files or programs downloaded from the internet
- Links sent via email or social media
- When inserting infected USB sticks
- When installing programs from unknown or unreliable sources
- Fraudulent websites
- Legitimate but infected websites
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How to protect ourselves from viruses
The best way to protect yourself from malicious programs is by installing an antivirus on your computer that has the ability to protect in real time to prevent viruses from entering and to allow deep scans to detect threats and eliminate them.
However, it is not enough just to have the best antivirus installed, it must always be updated. In this way, you ensure that you have the latest version of the virus database and it will be able to detect even the most recent and dangerous threats.
But, do not leave all the work to the antivirus, it is necessary to use common sense. This means being careful about the files you open, the websites you visit, and especially what you download from the Internet and the links you click on.
