# Malware

URL: https://softwaredictionary.org/terms/malware
Category: Security
Last updated: 2026-10-03
In Turkish: Kötü Amaçlı Yazılım
Pronunciation: MAL-wair

In short: Malware (malicious software) is any program designed to harm a computer or its user by stealing data, spying, damaging files or taking control of the system.

## What is malware?

Malware comes in several forms. A virus attaches itself to other files and spreads when they run; a worm spreads across networks on its own by exploiting vulnerabilities; a trojan pretends to be useful software; spyware and keyloggers secretly record what you do; rootkits hide deep in the system; and ransomware encrypts files and demands payment. Infected machines are often joined into botnets that attackers rent out.

Most malware arrives through people rather than clever hacks: an email attachment, a fake software update, a cracked program, a malicious browser extension or a poisoned package in a developer's dependencies. Unpatched software and exposed services let worms and attackers in without anyone clicking anything.

Defenses work in layers. Keeping systems and dependencies updated closes known holes; endpoint protection detects suspicious behavior; least privilege limits what malware can reach; email filtering and training reduce phishing; application allowlists and code signing stop unknown programs; and backups make recovery possible when something gets through.

A common misconception is that macOS, Linux or phones don't get malware. Every widely used platform is targeted, and developers are an attractive target because their machines hold source code, cloud credentials and signing keys, which is why supply chain attacks through packages and build tools have grown so much.

## Key takeaways

- Malware is software built to harm, spy, steal or take control.
- Viruses, worms, trojans, spyware, rootkits and ransomware are common types.
- It usually arrives through phishing, fake downloads or poisoned packages.
- Updates, least privilege, endpoint protection and backups defend against it.
- Every platform is targeted, including developers' machines.

## Frequently asked questions

**What is the difference between a virus and malware?**

Malware is the umbrella term for all malicious software. A virus is one type that spreads by infecting other files. Worms, trojans, spyware and ransomware are other types.

**How does malware get onto a computer?**

Most often through phishing emails and attachments, fake or cracked software, malicious browser extensions, compromised websites, infected USB drives and unpatched vulnerabilities in exposed services.

**Can developers' packages contain malware?**

Yes. Attackers publish packages with names similar to popular ones, or take over legitimate ones, so that installing them runs malicious code. Reviewing dependencies and using lockfiles and audit tools reduces the risk.

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Software Dictionary: https://softwaredictionary.org/ · https://softwaredictionary.org/llms.txt