Four hackers, four reasons
One hacker wants to make a point. One works for a government. One wants customer records to sell. One just wants to show off.
They all break into systems. Their reasons are different, and so is the harm.
Today you learn who they are and four ways they get in.
Key words
| Word | What it means | Example |
|---|---|---|
| Hacker | A person who gets into computer systems. | a thief or a tester |
| Hacktivist | A hacker who attacks to push a political or social cause. | |
| Nation state | A government that uses hackers, usually to spy or disrupt. | |
| Organised crime | A criminal gang that hacks to make money. | |
| Brute force | Trying every possible password or code, one after another. | |
| Password cracking | Finding out a password by guessing or by trying many. | |
| Cross-site scripting | Making a web page run an attacker's code in other people's browsers. Short form: XSS. | |
| SQL injection | Typing text that changes the question a program asks its database. | |
| Buffer overflow | Putting more data in a space than it can hold, so it spills over. | |
| Database | An organised store of data. | |
| Query | A question you ask a database. | |
| Input | What a user types or sends to a program. | |
| Sanitisation | Cleaning input so that it cannot act as code. |
The cells students fill in are left blank in this preview.
By the end of this lesson
Note
I can name four kinds of attacker and four hacking attacks, and give one defence for each attack.
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.
Only attack the lab
Warning
This lesson shows no attack steps on real systems. The optional labs are your own private copy with no way out to the internet. Never try these ideas on a real system. Unauthorised access is a crime under the Computer Misuse Act 1990, even if you mean no harm.
Attackers have different goals
Hacktivists attack to push a cause. They may deface a site or leak data.
Nation states are governments. They spy, steal secrets or disrupt other countries.
Organised crime is a gang. The aim is money: stolen records, ransoms and fraud.
Individuals act alone. Some want fun or fame. Some want revenge.
Brute force tries every password
Password cracking means finding out a password. Brute force is one way: the attacker tries every possible password, very fast.
A short password has few possibilities, so brute force finds it quickly. A long password has billions.
Impact: the attacker logs in as you, maybe to your data warehouse (a big store of company data). Defences: long passwords or passphrases, MFA, and a lock after a few wrong tries.
Worked example: PINs and brute force
| PIN length | Possible PINs | At 100 tries a second |
|---|---|---|
| 2 digits | 100 | 1 second |
| 4 digits | 10000 | 100 seconds |
| 6 digits | 1000000 | 10000 seconds, nearly 3 hours |
The cells students fill in are left blank in this preview.