A computer virus is a malware-affected application or installable code or program. It can come in with your system with infected applications. Such as a document, folder, image, etc. Which can replace and expand after the first run on a victim system where social interaction is expected. Many viruses are harmful and can damage data, slow down system devices, and log keystrokes.
Most of the computer viruses target systems running Microsoft Windows. Macs, on the other hand, enjoy status as virus-proof super devices. In reality, Macs are not genetically safer. There are more Windows active users in the world than Mac users. And cyber criminals directly choose to write viruses for the operating system (OS) with the highest amount of possible victims.
Once a virus has successfully linked to a program, file, or document. The virus will lie dormant until someone opens the computer or device to execute its code. For a virus to affect your computer, you have to run the malware program, which in turn makes the virus code to be executed.
Types Of Computer Virus
1. Boot Sector Virus
A boot sector virus is a type of computer virus that infects the boot division of floppy disks or the Master Boot Record (MBR) of hard disks (some affect the boot area of the hard disk preferably of the MBR). The infected program runs when the system is booted or restart from an affected disk, but once loaded it will infect other floppy disks when located in the infected devices. While boot area viruses spoil at a BIOS level, they use DOS commands to expand to other floppy disks.
2. Web scripting virus
This web scripting virus exists in some links, ads, image placement, videos, and layout of a website. All those files may carry the malicious program in which when you click, the viruses will be automatically downloaded or will redirect you to any malicious virus affected websites.
3. Browser hijacker
This type of computer virus affects your web browser in which it will show you several websites. Typically, if you enter a domain name in the web search address bar, the browser hijacker will open several fake websites that may damage your machine. On the other hand, most trusted browsers have default features to prevent them before. So, you should use those types of web browsers.
4. Macro virus
Macro viruses mainly target applications and software that may contain macros. These viruses can send out a group of operations changing the performance of the program or any kind of software. For example, O97M/Y2K, Bablas, Melissa.A, and Relax, these are all macro viruses.
5. Direct Action Virus
A file infector can be a resident virus or maybe a direct action virus. A resident virus can installed itself and hide someplace in the memory of your personal computer(pc). Upon performance, it seeks out other important files, documents, or programs to damage. This virus consider to be “non-resident” and uses by choosing one or more files to infect every time the code performed.
6. Resident Virus
A resident virus is a kind of computer virus that saves itself within memory, enabling it to infect other files, documents even when the originally infected software is no longer running.
Being stored in memory permits the virus to grow easier because it has more entrance to other parts of the computer. Like, a memory-resident virus could be in memory when a writable solid or hard drive is connected, or a diskette is entered into the computer. Once initialized, the virus could spoil the drive or diskette and grew itself to any other devices that use that drive or diskette.
7. Multipartite Virus
This type of virus can quickly spread in your computer system. It is very dangerous, operating unauthorized actions in your operating system, files, documents, and other programs on the computer. They can infect both the runnable files and the boots division.
8. Polymorphic Virus
Polymorphic viruses are complicate file infectors that can produce modified versions of itself to avoid discovery yet maintain the same basic methods after each infection. To modify their physical file makeup during every infection, polymorphic viruses encrypt their program and use various encryption keys every time.
9. Overwriting Virus
An overwriting virus ( overwriting infector) is a malicious program that, after infection, will completely ruin the original program code, basically by overwriting or replace data in the system’s memory (overwrites the host program). Many reflect replace viruses to be remarkably harmful because they damage elements of a user’s system.
10. Spacefiller Virus
A spacefiller virus also known as cavity virus or Chernobyl virus or CIH is a unique type of computer virus that tries to install itself by filling in blank sections of a folder. By only utilizing empty parts of a file, the virus can infect a folder without altering the size of the file, making it tougher to disclose.
It is Microsoft Windows 9x computer virus which first time appeared in 1998. It hit Windows 95,98 and ME. Its payload is very detrimental to unprotected systems, overwriting significant information on infected system drives, and in some cases damaging the system BIOS.
11. File Infector Virus
A virus that appends itself to executable programs. Once the original infected application run, the virus changes to the processor memory and may replicate itself moreover, increasing the infection. This type of virus can expand behind one’s system as quickly as the infected file or application transferred to another computer. The easiest form of these viruses operates by overwriting a portion of the application they are infecting. More advanced versions hide their behavior by saving the record or file’s primary directions so that these are performe even after infection.
12. Companion Virus
This is a type of virus that doesn’t sustain without bringing an existing file or folder. To bring out damages, the file or folder being conduct by companion viruses should be opened or executed. Some examples of these viruses include Terrax.1069, Stator, and Asimov.1539 also, which is serious.
13. Encrypted Virus
This type of virus utilizes encrypted wicked codes which make antivirus software difficult to identify. They can only be exposed when they decrypt or allow themselves to detect during replication. Although they don’t remove files or folders, they can seriously harm PC performance.
So, Never underestimate to take action on a computer virus living in your system. There are possibilities that you force end up losing valuable files, programs, and papers. In some cases, the virus infects the system device too. Whereby, it becomes compulsory to have effective and paid anti-virus software installed on your computer to direct clear of all such virus and threats.