Malware
About 2 min read
Last updated: 2026-08-24
What Is Malware
Malware is a portmanteau of "malicious" and "software," referring to any software intentionally designed to harm computers, networks, or users. The term "computer virus" is technically just one type of malware.
The categories are defined by behaviour (what a sample does and how it spreads), so a single specimen often falls into several of them at once. A classic combination is code that slips in disguised as a harmless utility (trojan) and then stays resident, sending everything you type out to an external server (spyware).
Types of Malware
Infection Routes
Common infection routes: (1) Email attachments and links (2) Unintended downloads that begin the moment you open a compromised site (drive-by downloads) (3) Malicious ads slipped into legitimate ad networks (malvertising) (4) Fake installers posing as genuine software (5) External media such as USB drives (6) Exploitation of software vulnerabilities.
Malvertising abuses the ad delivery path itself, so the entry point can be an ad displayed on a reputable site you visit every day. That is what makes this route awkward: avoiding dubious sites is not enough to shut it out.
Warning Signs and Prevention
Warning signs: sudden slowdowns, unknown programs running, files modified without your knowledge, excessive pop-up ads.
Prevention: apply operating system and software updates as they are released, avoid opening untrusted files, install security software, and back up your data regularly.
Security software detects mainly by matching known signatures and behaviour, so it cannot be relied on to catch every fileless attack or unknown variant. The foundation is layered habits: updates, backups, and care with attachments. Keeping at least one backup copy in a place the infected machine cannot overwrite (offline media, for example) makes recovery far more certain.
For more details, see our article What Is Malware? Types and Prevention Explained.
Common Misconceptions
- Macs and smartphones cannot get malware
- While less common than on Windows, Macs and mobile devices can and do get infected with malware.
- Antivirus software provides complete protection
- New malware variants can evade antivirus detection. Behavioral precautions are equally important.
Virus vs. Malware
Malware
An umbrella term for all malicious software, including viruses, worms, trojans, and more.
Virus
A specific type of malware that attaches to files and replicates through user action.