What Is Malware?

Malware Short Definition:
Malware, short for malicious software, is any type of an intrusive software program, created to harm and/or destroy computers or computer systems. Examples of malware include computer viruses, worms, trojans, spyware, ransomware, and adware (depending on the type of the program itself).

Malware: Extended Definition

Regardless of its type, malware aims to get downloaded onto the targeted system. This could be achieved via various distribution techniques, including phishing emails (where the victim is prompted to click a link), visiting malicious sites (with the same purpose), downloading a trojanized application (i.e. from a torrent website), or using peer-to-peer sharing services. Including a piece of malware in a torrent is a widespread distribution tactic. Note that mobile devices are also prone to malware infestations.

Malware can also be downloaded from a USB drive. Infected drives are often the cause of malware infections.

Once the malware installation has been completed, the victim’s device could be affected in various ways. In the case of ransomware, your files are encrypted. In the case of a trojan infection, you may not notice right away that something is wrong with your machine. This is because trojans tend to stand silent on the compromised system. You can read more about trojans in our dedicated trojan article.

Also note that malware can be designed to target either individual users or organizations. In the latter case, malware is very sophisticated and in some cases is state-sponsored. This type of malware usually is called Advanced Persistent Threat, or APT.

For more definitions, check out our Cyber Dictionary.