What is Virus

‘VIRUS’ is an acronym for Vital Information Resources under Seize. A computer virus is a piece of code which is capable of copying sensitive information from a computer or completely destroying the data. A virus has the potential to cause unexpected changes or damages to systems, such as corrupting the system software or permanently damaging hard disk, without the user’s knowledge.

A virus can be spread through an email attachment, by clicking on an executable file or an infected website or advertisement. It can also spread all the way through storage devices like flash drives or USB drives. The moment a virus takes a host, it infects the entire system software or resource and modifies the core functions of applications or may copy, delete and encrypt the data. Some viruses begin to spread as rapidly as they infect the host, but other viruses remain stable, without showing major signs or symptoms of existence in a system. It gets triggered only when an instruction code is executed by the gadget or system.

In 1971, Robert Thomas, an engineer at BBN Technologies developed the first computer virus known as the "Creeper" virus, which was an experimental program, reports TechTarget.

Types of Viruses

File Infectors: Usually the file infectors like .com or .exe files connect themselves to program files. The virus infects the program through the type of files like .sys, .ovl, .prg, and .mnu files that are executed during running a program. Other file infector viruses come along with the programs or scripts sent as an attachment to the email.

Macro Viruses: These viruses particularly aim applications like Microsoft Word or similar type of applications and cause a series of actions performed without the user’s consent. The first macro virus appeared in July 1995, mostly infected word documents and became a dominant type virus, until the Microsoft disabled macros by default in Office 2000 version.

Overwrite Viruses: These viruses are specifically designed to wipe out a file or application's data. An overwriting virus begins to overwrite files with its own code after infecting a particular application present on a device. It can install new codes in files and applications that programs to run the virus and spread to other files existing in the system.

Rootkit Viruses: A rootkit virus is a sort of malware that installs an unauthorized rootkit on an infected system, giving attackers complete command over the system to fundamentally modify or disable functions and programs. Rootkit viruses were especially designed to evade antivirus software, which usually scans only applications and files. The recent versions of antivirus and anti-malware programs include rootkit scanning to recognize and mitigate such kinds of viruses.

Some viruses are designed intentionally with financial gains in mind, while others can have deep and damaging effects, such as erasing data or causing permanent damage to the hard disk.

To avoid contact with a virus it is important to be cautious while surfing the web, downloading files, and opening links or attachments. The best method is to avoid downloading text or email attachments or files from websites that look suspicious.