Malware (short for malicious software) is any software designed to harm, exploit, or disrupt computers, systems, networks, or data. Attackers use malware to steal information, damage systems, gain unauthorized access, or cause disruption.
Malware spreads through:
A virus attaches itself to a legitimate program or file and spreads when the infected file is executed.
A worm is a self-replicating malware that spreads automatically across networks without user action.
A Trojan looks like a legitimate application but contains malicious code.
Ransomware encrypts a victim’s data and demands payment (ransom) to unlock it.
Spyware secretly monitors user activity and collects information such as passwords, browsing habits, and credit card details.
Adware displays unwanted advertisements on devices.
Rootkits hide malicious activities by giving attackers unauthorized root or admin-level access.
Keyloggers record every keystroke typed on a keyboard.
A botnet is a network of infected computers (bots) controlled by an attacker (botmaster).
A type of malware that operates in memory without relying on files.
A backdoor bypasses normal authentication to give attackers secret access.
Malicious code triggered by a specific event (date, action).
| Malware Type | Key Feature |
|---|---|
| Virus | Attaches to files, needs execution |
| Worm | Self-replicates, spreads automatically |
| Trojan | Disguised as legitimate software |
| Ransomware | Encrypts data for ransom |
| Spyware | Monitors and steals information |
| Adware | Shows unwanted ads |
| Rootkit | Hides malicious activity |
| Keylogger | Records keystrokes |
| Botnet | Network of infected devices |
| Fileless Malware | Runs in memory, hard to detect |
| Backdoor | Secret unauthorized access |
| Logic Bomb | Activated when conditions are met |
Malware is a major threat in cybersecurity, with different types designed to steal data, disrupt systems, or take control of devices. Understanding these types helps in applying proper defenses like antivirus, firewalls, updates, and user awareness.
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