What is malware?
Definition
Malware, short for malicious software, is any software or firmware placed on a device on purpose to harm it or its owner: to steal data, spy on activity, lock files or damage systems.
- Category
- Attacks
- Also called
- malicious software, malicious code
- Last updated
"Malware" is short for malicious software. NIST's glossary describes it as hardware, firmware or software deliberately placed in a system for harmful purposes, and as software an adversary designs to violate a computer's security. Viruses, spyware, rootkits and Trojan horses all fall under it.
How malware gets onto a device
Malware has to be installed, and often you do it yourself without knowing. The common routes are an attachment or link in a phishing email or text, a fake app or software update, a booby-trapped download, or a USB drive. Attackers also use known flaws in software you haven't updated. Many attacks start with social engineering: a believable message that talks you into opening the file.
Common types
- Viruses and worms copy themselves to other files or devices.
- Trojans pose as something useful while doing something else.
- Spyware secretly gathers information about people or organizations. That can include keystrokes, passwords and browsing.
- Ransomware locks your files and demands payment to unlock them.
- Rootkits hide other malware deep in a system.
A typical case: you get an email that looks like an invoice, open the attached file, and a program quietly starts recording what you type, including your banking password.
Why it matters
Malware can steal passwords, card numbers and personal details, which then feed identity theft and account takeover. It can also hand control of your device to someone else.
Malware vs. virus
A virus is one kind of malware. People often say "virus" for everything, but malware is the broader term, and most modern threats are not viruses in the strict sense.
How to protect yourself
- 1
Keep everything updated
Turn on automatic updates for your operating system, browser and apps. Updates close the flaws malware uses.
- 2
Install apps and software only from official sources
Use your phone's official app store or the maker's own website. Be suspicious of cracked software and "required" plugins from pop-ups.
- 3
Don't open unexpected attachments or links
Check with the sender through another channel first. This also protects you from phishing.
- 4
Run security software and back up your files
Use the antivirus built into your system or a reputable one, and keep an offline or cloud backup so ransomware can't hold your only copy hostage.
- 5
If you think you're infected
Disconnect from the internet, run a full scan, and change your passwords from a different, clean device. Turn on two-step verification on the accounts that matter most. Serus also monitors the dark web and breach databases and alerts you if your email or passwords appear, so you know what to change.
See where your personal data is exposed
Serus finds it on data brokers and people-search sites and removes it.
Frequently asked
What does malware stand for?
Malware is short for "malicious software".
What is the difference between malware and a virus?
A virus is one type of malware, one that copies itself into other files. Malware also includes spyware, ransomware, Trojans and more.
How do I know if I have malware?
Common signs include a device that suddenly runs slowly, unexpected pop-ups, apps you didn't install, battery drain and settings that change by themselves. Some malware shows no signs at all, so regular scans help.
Can phones get malware?
Yes. Phones can get malware through fake apps, malicious links and texts. Installing apps only from official stores and keeping your system updated lowers the risk.
Sources
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