Malware is a general term that describes lots of different programs that try to do something unwanted to your computer. Anti-virus software prevents malware from attacking your computer or mobile device. There are free anti-virus applications available:

• AVG
• Avast!
• Microsoft Security Essentials

There are also applications that you have to pay for:

• Norton
• McAfee
• Sophos

There are many types of malware:

• A virus harms your computer in some way, usually by deleting or altering files and stopping programs from running.
• A trojan starts by pretending to be a trusted file, but gives unauthorised access to your computer when you run it.
• Worms are difficult to get rid of. They copy themselves over networks to external storage devices
• Spyware collects information from your computer and sends it to someone.
• Scareware tricks you into thinking it’s software that you need to buy.

Firewall

A firewall monitors connections to and from your computer. If it spots something suspicious, it closes the connection or disconnects it. Most operating systems include a firewall and it should be turned on by default.

Hackers, people who try to gain access to your computer without your permission, will have a harder time if your firewall is enabled.