Computer Management Grade 11
Safeguarding a computer system requires understanding threats, knowing how malware works, and applying the right remedies.
Human Error Threats
- Sharing sensitive information with wrong people
- Writing down or reusing passwords
- Clicking links without verifying them
- Leaving devices unlocked / unattended
- Accidentally deleting valuable data
Physical Threats
- Theft of devices or storage media
- Hard drive mechanical failure (moving parts)
- Power surges or outages damaging hardware
- Water/liquid spills causing short circuits
Malware
| Type | Description |
|---|
| Virus | Attaches to files; replicates when file is run; causes damage |
| Worm | Spreads across networks without user action |
| Trojan | Disguised as useful software; gives attacker back-door access |
| Rootkit | Hides in OS; gives remote attacker control; avoids detection |
| Ransomware | Encrypts data; demands payment to restore access |
| Spyware | Secretly monitors activity and steals data |
| Adware | Displays unwanted pop-up advertisements |
Network Vulnerabilities
| Attack | Description |
|---|
| Phishing | Fake official-looking emails to steal credentials |
| Pharming | Redirects users to fake websites |
| Spoofing | Forges sender addresses to impersonate someone |
| SQL Injection | Malicious SQL commands entered via web forms |
Remedies and Protection
| Remedy | Purpose |
|---|
| Antivirus | Detects, removes and prevents malware infections |
| Firewall | Filters all incoming and outgoing network traffic |
| Strong passwords | 8+ chars; mix of uppercase, lowercase, numbers, symbols; unique per site |
| User access rights | Users only access files they are authorised for |
| Encryption | Scrambles data so it cannot be read if intercepted |
| UPS | Keeps computer running during power failure |
| Software updates | Patches fix known security vulnerabilities |
| 2FA / MFA | Requires additional verification beyond just a password |
Backups
| Type | Description | Restore speed |
|---|
| Full backup | Copy all files every time | Fastest |
| Incremental | Only files changed since last backup (any type) | Slowest to restore |
| Differential | Files changed since last full backup | Moderate |
Backup Locations
- Local — external HDD at same location (fast, but vulnerable to fire/theft)
- Off-site — physical device at another location (protects against local disaster)
- Cloud — Google Drive, OneDrive (automatic, accessible anywhere)
3-2-1 Backup Rule
3 copies, on 2 different media types, 1 stored off-site or in the cloud.