The guard at the door
Think of a school building. A guard checks bags at the door. Another checks what people carry out. A third walks the halls looking for anything odd.
A computer has the same three jobs done by software. One checks files. One checks what comes in and goes out. One locks the wireless signal.
By the end of this lesson
Note
I can explain how three kinds of protection keep a device and its wireless signal safe.
Key words
| Word | What it means |
|---|---|
| Malware | software made to cause harm |
| Antivirus | software that finds and removes malware |
| Signature | a known pattern that identifies one piece of malware |
| Heuristic | a method that spots odd behaviour, not only known patterns |
| Firewall | a filter that blocks unwanted network traffic |
| Network | devices joined so they can share data |
| Encryption | scrambling data so only the right people can read it |
| Quarantine | a safe place where a suspect file is held |
The cells students fill in are left blank in this preview.
Starter: what you already know
Have a go
Starter: what you already know
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.
Antivirus looks for malware
Antivirus software scans files and programs. It uses two main methods.
The first uses signatures. A signature is a known pattern of one piece of malware. The software compares each file with its list. This is fast and accurate for known malware, but it misses new malware. The second is a heuristic method. It watches for odd behaviour, such as a program trying to change many files. It can catch new malware, but it sometimes raises a false alarm.
What antivirus does with a threat
| Step | What happens |
|---|---|
| Scan | Files are checked when opened, and the whole device is checked on a schedule |
| Detect | A signature match or odd behaviour raises an alert |
| Deal with it | The file is cleaned, held in quarantine or deleted |
| Report | The user or the IT team is told |
| Update | The list of signatures is refreshed, often every day |
The cells students fill in are left blank in this preview.
Check
Have a go
Check
3 questionsYour answers are marked here and are not kept. A college account keeps every student’s marks.