What’s the difference between virus’, spyware, malware? The terms virus and malware get thrown about almost interchangeably in today’s world, along with spyware, but what do they actually mean?

Like a real life virus, a computer virus injects malicious code into a previously innocent program, such that when that program is run it will perform the virus’ malicious commands (usually to infect other files), and usually likes to keep a low profile until it delivers its “payload”, which traditionally was to be destructive and delete files but these days virus’ are more likely to force your computer to be part of a DDoS attack, or steal information.

Spyware is defined as software that steals information on your computer, and is not mutuallyexclusive with a virus, a virus can be spyware but spyware is not necessarily a virus. Similarly, adware is software that pops up unwanted advertisements (think those random popups in web browsers that appear on trusted sites like Facebook for apparently no reason).

Computer worms are similar to virus’, however they don’t infect other programs but rather copy themselves onto other computers the worm can reach on the network or sometimes onto removable disks like USB drives and attempts to attach itself onto running processes asa DLL file.

Trojans, just like in the movie Troy, are like the Trojan Horse and hide within other working programs concealing their true purpose until it delivers its virus payload, these programs canbe perfectly legitimate programs that were just modified to include the Trojan virus and can be dormant for some time before they become malicious. Some spyware is delivered through a Trojan.

Scareware is another malware, and refers to software that pretend to be antivirus programs and notify you at some point that you have a virus on your computer, and the only way to remove it is to register the program, or download another program, or some other way of making you pay to remove the infection. They use fear in order to cause you to make a rash decision, hence the same scareware. Scareware is not the same as ransomware (which doesn’t pretend, it simply locks up your data and forces you to pay for it to be unlocked).

Finally, malware is a large umbrella term for all these things listed above, and anything your antivirus scanner should be able to remove, short for malicious software, ie anything that has ill intentions for your computer and other computers.

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