What is a computer virus?

A computer virus is software that enters your computer system without your knowledge or permission, and ‘infects’ your computer programs with malicious codes.

For example, a virus might attach itself to a program such as Microsoft Word. Each time the Word program runs, the virus runs too. A virus can reproduce by attaching itself to other computer programs, files or a hard drive, and can cause havoc.

Here are some different types of computer infections:

• Adware is software that causes pop-ups and banner adverts in order to generate revenue. It may not do any damage to your device, but it might be able to access your personal information.

• Malware is short for ‘malicious software’ and means any program or file that is harmful to your computer. It includes viruses, worms, Trojan horses and spyware.

• Ransomware is a type of malware that threatens to publish the victim’s data or block access unless a ransom is paid.

• Spyware is software that helps to gather information about a person or organisation without their knowledge.

• A Trojan horse is malicious code disguised as, or contained within, software that looks legitimate. It can install hidden software to gain access to the users’ systems, usually to steal data or cause data loss.

• A worm is a malicious piece of software that replicates itself in order to spread to other computers.

Here are some tips (adapted from Dell Technologies, 2020) to help you protect your computer from viruses and other malware:

Never download and install software unless you are certain it is from a trusted source.

Install antivirus software that can detect, block and eliminate all types of computer viruses.

Keep your antivirus software up to date, as well as running regular scans.

Do not open email attachments unless you have scanned them first. Even a picture can carry a virus.

Install an anti-malware program to prevent software from being installed on your device without your knowledge.

Install anti-spyware software to prevent software tracking your activities or scanning your computer for personal information.

Don’t trust modified software (cracked or hacked software), as it often contains malware.