What Is Malware?
Malware is a broad term for any software designed to harm you, your device, or your data — without your consent. It covers viruses, ransomware, spyware, and adware. It can arrive via email attachments, malicious websites, or even infected USB drives.
The Main Types of Malware
Virus
Malicious code that attaches to legitimate files and spreads when those files are opened or shared. The oldest and most widely known form.
Ransomware
Encrypts your files and demands payment to restore access. The most financially damaging type for individuals and businesses.
Spyware
Silently monitors what you type, which websites you visit, and sometimes your webcam. Used to steal passwords and financial details without triggering any visible alert.
Adware
Floods your browser with unwanted adverts and redirects. Less dangerous but highly disruptive and often a sign of a larger problem.
Trojans
Disguise themselves as legitimate software. Once installed, they create a hidden backdoor giving criminals remote access to your device.
Keyloggers
A form of spyware that records every key you press, capturing passwords, bank details, and personal messages as you type.
How Malware Gets onto Your Device
- Email attachments — clicking what appears to be an invoice, delivery notification, or document
- Malicious websites — sites designed to look legitimate but containing hidden download code
- Unofficial software downloads — pirated programs or downloads from untrusted sources
- Infected USB drives — plugging in a drive that carries hidden malicious code
- Outdated software — unpatched vulnerabilities in your operating system or browser that criminals exploit
Signs Your Device May Have Malware
- ⚠️Running significantly slower than usual
- ⚠️Browser redirecting to unexpected websites without you clicking anything
- ⚠️Pop-up adverts appearing even when no browser is open
- ⚠️Device getting very hot or the fan running constantly at high speed
- ⚠️Programmes opening or closing by themselves
- ⚠️Contacts receiving messages you did not send
- ⚠️Unusual charges or account activity
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Start for free →How to Check for and Remove Malware
Step 1: Run a security scan
- • Windows: Windows Security → Virus & Threat Protection → Quick Scan (free, built in)
- • Mac: Malwarebytes free version (download from malwarebytes.com)
- • Android: Malwarebytes or Bitdefender (avoid unverified antivirus apps from unknown developers)
- • iPhone: iOS is tightly controlled — malware is rare. Focus on app permissions and account access instead.
Step 2: Disconnect from the internet
While the scan runs, to stop any malware communicating with criminal servers.
Step 3: Follow the removal steps
The security software recommends.
Step 4: Change your passwords
If malware was present, treat your passwords as potentially compromised.
Related guides
Frequently asked questions
What is malware in simple terms?
Malware is any software designed to damage your device or steal your information without your knowledge or consent. It includes viruses, ransomware, spyware, and more.
How do I know if I have malware?
Common signs include your device running slowly, unexpected pop-up adverts, browser redirects to unfamiliar websites, unusual account activity, or programmes opening by themselves. Run a free scan with Windows Security or Malwarebytes.
Can malware be removed without a professional?
Yes, in most cases. Windows Defender and Malwarebytes can detect and remove most common malware. More serious infections — particularly some ransomware strains — may require professional assistance or a full device reset.