Fighting malware

How malware spreads: through downloads from the Internet, spam email attachments and links, removable storage such as pen drives, and networks.

Warning signs that a computer may be infected:

• frequent pop-up windows;
• the browser's home page changes by itself;
• mass emails sent from your account without your knowledge;
• the computer becomes slow, or crashes often;
• unknown programs appear, or start by themselves;
• storage space goes missing.

Prevention is better than cure:

• Install antivirus software and keep it updated.
• Install software updates (patches), which fix security holes.
• Keep regular backups of important data.
• Use a firewall.
• Never use pirated software.
• Be careful with links and attachments, and on public Wi-Fi.

How antivirus software finds malware:

• Signature-based: each known virus has a pattern, its signature, stored in a virus definition file (VDF). The antivirus scans files for these patterns. A VDF that is out of date cannot recognise new viruses, so it is as good as no antivirus.
• Sandbox: a suspicious program is run in a safe, isolated space, and watched to see what it does.
• Data mining: studying a program's features to classify it as harmful or safe.
• Heuristics: looking for suspicious behaviour or code, to catch new, unknown malware.
• Real-time protection: constantly watching the computer for malicious activity.