TL;DR
Malware is any software designed to harm, exploit, or compromise systems. Types include ransomware (encrypts files for ransom), spyware (steals data), trojans (disguised as legitimate software), and worms (self-spreading). Malware typically arrives via phishing, infected downloads, or exploits. Protect against it with updates, endpoint protection, user training, and backups.
The Simple Explanation
Malware is bad software. Someone writes code to do something harmful: steal your data, encrypt your files for ransom, spy on you, or use your computer for attacks. It gets on your system through tricks (phishing), exploits (unpatched vulnerabilities), or deception (fake software). Once there, it does what the attacker designed it to do.
Types of Malware
| Type | What It Does | Goal |
|---|---|---|
| Ransomware | Encrypts files | Extort payment |
| Spyware | Monitors activity | Steal information |
| Trojan | Disguised as legit software | Gain access |
| Worm | Self-replicates across networks | Spread widely |
| Rootkit | Hides deep in system | Maintain access |
| Cryptominer | Uses your resources | Mine cryptocurrency |
How Malware Spreads
- Phishing: Email attachments or links
- Drive-by downloads: Compromised websites
- Fake software: Pirated or trojanized apps
- Malvertising: Malicious advertisements
- Exploits: Attacking unpatched vulnerabilities
- Physical: Infected USB drives
Signs of Infection
- System runs slowly or crashes frequently
- Unexpected pop-ups or ads
- Programs opening or closing on their own
- Files encrypted or missing
- Unusual network activity
- Antivirus disabled
- New programs you did not install
- Browser redirects to strange sites
Ransomware is growing. Attacks increased dramatically, targeting businesses of all sizes. Having offline backups is critical. If you are hit, backups let you recover without paying ransom.
Protection Measures
- Update software: Patch vulnerabilities
- Endpoint protection: Antivirus and EDR
- Email filtering: Block malicious attachments
- User training: Recognize phishing
- Least privilege: Limit installation rights
- Backups: Offline, tested recovery
- Network segmentation: Contain spread
What are the most common types of malware?
Ransomware encrypts files and demands payment. Spyware monitors activity and steals data. Trojans disguise themselves as legitimate software. Worms spread automatically across networks. Cryptominers hijack resources to mine cryptocurrency. Rootkits hide deep in systems to maintain access.
How does malware get installed?
Common infection vectors include phishing emails with malicious attachments, compromised websites (drive-by downloads), infected software downloads, malicious ads (malvertising), exploiting vulnerabilities in unpatched software, and USB drives. Social engineering tricks users into installing malware themselves.
How do I protect against malware?
Keep software updated to patch vulnerabilities. Use endpoint protection software. Train users to recognize phishing. Limit software installation permissions. Segment networks to contain infections. Maintain backups for ransomware recovery. Use application allowlisting on critical systems.