Virus

What is a virus?

Computer viruses are self-reproducing malicious software that wreak havoc on devices and spread from one file to another, then one device to another, frequently via email attachments, drive-by-downloads, and USB drives. Viruses need human action to spread.

What they are after

Most viruses attach themselves to executable files, but on occasion, they also affect MS Office macros, auto-run scripts, and the master boot record. Viruses are largely disruptive in nature: they display irritating messages, disrupt the functioning of a device, corrupt files, or delete them altogether. In certain cases, viruses can also steal information.

Known cases

The Concept Virus that was accidentally shipped on a CD-ROM by Microsoft in 1995.
Chernobyl virus used to strike every year on April 26, marking the anniversary of the Chernobyl nuclear accident.
The Melissa virus, which spread via email and allegedly caused $80 million in damage.

How to block viruses

Computer virus protection: Avira Free Antivirus protects you from viruses.

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