What is the Difference Between Malware and Viruses?

Question from Reader:

I hear a lot about malware and virus threats. It seems that some articles I read call a threat ‘malware’ while others call what seems like the same threat a ‘virus’. Is there are a difference?  

Answer from Hoax-Slayer:

The term ‘malware’ is derived from the two words ‘malicious software’ and describes any piece of malicious code that can infect your computer and perform unwanted activities such as stealing information and allowing criminals to use your computer for their own purposes.

A ‘virus’ is a specific type of malware that can replicate and spread itself (like a biological virus). Thus, technically, computer viruses are actually just a subset of malware.

In fact, true computer viruses are quite rare these days and are considered much less of a threat. Criminals have moved to other types of malware that better achieve their nefarious goals.

Nowadays, although perhaps not technically correct, the terms ‘malware’ and ‘virus’ tend to be used interchangeably. If you see a news article warning about a computer ‘virus’, it is probably referring to a malware threat in general rather than a threat involving a true, self-replicating virus like those of days gone by. 

Language evolves rapidly, so it is hardly surprising that the original meaning of the term ‘virus’ – as applied to computing – has shifted a little so that it now tends to encompass all malware rather than just a specific malware type.

But, some confusion arises because the software used to protect your computer from malware (including viruses) is still generally referred to as ‘antivirus’ software. When these programs were first developed, true computer viruses were the type of malware threat that security firms were most concerned about. The companies therefore marketed the software as ‘antivirus’ software.

Modern antivirus software is designed to protect your computer from many kinds of malware, not just viruses. But, the ‘antivirus’ name has stuck and will likely remain with us for some time yet.