A hacker gains unauthorized access to computer systems to steal or corrupt data, often for the challenge. Hacking is illegal. To prevent hacking, use complex passwords, update security software, install a firewall and antivirus, and be wary of public WiFi and email attachments. Viruses are programs that infect computers without permission and can delete or corrupt data. They spread through email attachments and downloads. Installing antivirus software and keeping it updated prevents viruses. Worms replicate faster than viruses and use system resources to take over computers. Firewalls, antivirus, and disabling JavaScript help prevent worms. Trojans disguise as legitimate software but install malware for remote access to steal data and monitor users.

2. Hacking
A hacker is someone who gains unauthorised access to computer systems for
the purpose of stealing and corrupting data.
A hacker will break codes and passwords to gain access to the system.
May hack to for the challenge, or may hack to gain access to potentially
valuable data.
Hacking (technically known as cracking) is illegal and carries a possible
prison sentence.

3. Hacking
To avoid being hacked:
Use complex passwords
Change passwords regularly
Avoid using same passwords across different sites
Ensure OS and browser security updates are installed
Install a firewall
Install Anti-virus software
Be wary of clicking email links and attachments
Be wary of public wi-fi

4. Viruses
A virus is a program or piece of code that is loaded onto a computer without
the user's knowledge and performs harmful actions.
Viruses can replicate themselves.
All computer viruses are man-made.
Viruses can:
corrupt or delete data
use email to spread to other computers
erase the entire hard disk
display messages on screen
prevent a computer from starting up

5. Viruses
Viruses are spread by
attachment in email messages
downloading a file from the internet
infected web pages
removable media (USB stick, CD-ROM)
Viruses can be prevented by
Installing Anti Virus software
Ensuring Anti Virus Software is always up-to-date
Avoid opening email attachments or downloading
files from untrusted sources

6. Worms
A worm is a computer program which spreads malicious code across a
network
The main difference between a virus and a worm is that a worm has the
capability to replicate itself whereas a virus requires human interaction to
replicate.
Worms can spread very quickly and use up system resources, bandwidth or
allow malicious users to take over computers.
Worms can be prevented by:
Installing Anti Virus software and keeping it up-to-date
Installing a firewall
Turning off JavaScript when web browsing

7. Trojan
A Trojan is a type of malware disguised as legitimate software but which is
designed to provide unauthorised, remote access to a user’s computer.
Trojan's create a “back door” and can:
assist an attacker turning computer into a zombie
allow the attacker to install malware or a key logger
gain access to personal details and data