Malware (malicious software) is any software intentionally designed to cause disruption, damage, gain unauthorised access, steal data or extort money from users. It encompasses a wide range of threats from viruses to ransomware.
Types of Malware
- Virus — Attaches to legitimate files and spreads when they are executed.
- Worm — Self-replicates across networks without needing a host file.
- Trojan — Disguised as legitimate software to trick users into installing it.
- Ransomware — Encrypts the victim's files and demands payment for the decryption key.
- Spyware — Secretly monitors and records user activity.
- Adware — Displays unwanted advertisements, often bundled with free software.
- Keylogger — Records keystrokes to steal passwords and other sensitive input.
- Cryptojacker — Uses the victim's CPU to mine cryptocurrency without consent.
- Rootkit — Hides deep in the OS, giving attackers persistent privileged access.
How Malware Spreads
- Email attachments and links.
- Malicious websites and drive-by downloads.
- Infected USB drives.
- Software from untrusted sources.
- Exploiting unpatched software vulnerabilities.
Signs of Infection
- Unexpected slowdown or crashes.
- Unusual network activity.
- Unexpected pop-ups or browser redirects.
- Files being encrypted or disappearing.
- Antivirus alerts.
Prevention
- Keep OS and applications updated.
- Use reputable antivirus software.
- Never open attachments from unknown senders.
- Download software only from official sources.
- Back up important data regularly.