Types of computer viruses
Start sector virus
Viruses in the boot sector became popular because computer startup floppy disks are used. The widespread use of the Internet and the death of the flop have intensified other methods of spreading the virus.
This type of virus, which can spread in many ways, including voluntary downloading, effectively hijacks certain browser features, usually in the form of automatic redirection of the user to certain websites. It is generally assumed that the purpose of this tactic is to increase revenue from online advertising.
Direct action virus
Unlike most, this type of virus only takes effect when the file that contains the virus runs. The payload is delivered and then the virus is basically dormant – it does not take any other action unless the infected file is re-run.
Most viruses do not use a direct method of reproduction just because they are not productive, but these types of viruses have done damage in the past.
File infection virus
Perhaps the most common type of virus, file infection takes root in the host file, and then starts working while the file is running. The virus can overwrite the infected file or only part of the file, or replace the file again so that the virus works instead of the program that the user intends. Macro viruses are viruses that use the macro programming language of an application to self-implement. Typical macro virus infected people are MS Word and MS Excel documents that spread to other similar documents.
Although some viruses prefer to spread by one method or deliver one payload, the viruses in several batches have it all. This type of virus can spread in several ways, and it can perform various actions on an infected computer, depending on variables such as the installed operating system or specific files.
The polymorphic virus not only replicates by creating multiple files itself, but it also changes its digital signature every time it is replicated. Make it harder to detect less advanced antivirus software.
The aim of this trick is avoidance. Antivirus software uses the code you use frequently to detect viruses. If you hide or change the virus code, you can avoid detection. This extensive virus definition applies to all viruses that enter system memory. It can then do any number of actions and perform regardless of the file that was originally infected.
The ground virus is directly comparable to a payload virus that cannot access the system’s memory, so it only intervenes when the infected file is run. Many websites use complex code to provide interesting content. For example, to watch an online video in a browser, you need to run a specific encoding language that provides both the video itself and the player interface.
Of course, this code can sometimes be exploited, allowing the virus to infect your computer or take action on a computer through a website. Although malicious websites are sometimes created with deliberately infected code, there are many such cases of virus caused by the addition of code to the website without the knowledge of the web manager.
Trojan Horse Virus
The Trojan virus is one of the most common and destructive computer viruses that appear to have a useful feature. It’s different from a common computer virus because Trojan horse viruses don’t replicate themselves. One of the most insidious trojan horse types is a program that claims to free your computer from viruses, but instead brings viruses to your computer. Trojan viruses can also create a backdoor on your computer that allows malicious users to access your computer, which can damage confidential or personal information. Worm is a malware that can make copies of it itself, it is designed to spread through computer networks. It is one of the most dangerous forms of computer viruses. It can be found mainly in spam attachments or messages with executable scripts. The worm is also known as malware.