Online security problems facing home users and small businesses are different from those facing larger companies and corporations.

Here are threats you may meet:

• Malware: Is the generic name for all malicious software. Some people also talk of greyware which refers to software that’s annoying but not dangerous.
• Virus: A small program designed to automatically copy itself from one computer to another. Viruses attach to other pieces of software or hidden inside images, games and music files. They usually travel from machine to machine by email, instant messaging or file transfers. Although some viruses are harmless, most are disruptive, the worst can stop a PC from working.
• Worm: Also a self-replicating program, but unlike viruses, worms can automatically travel from machine to machine without being attached to other pieces of software. This means in addition to any other damage they slow networks because they can consume bandwidth.
• Trojan: The name given to a program which looks harmless, but has an unexpected malicious purpose. Some start their mischief immediately, others may wait, possibly collecting data without the computer owner’s knowledge.
• Spyware: A program designed to collect information about a computer and its user that the spyware author can use to make money. Typically spyware may watch your web browsing and target pop-up advertising at you or divert you to other web sites.
• Rootkit: A program designed to change a computer’s operating system to hide the behaviour of other malware.
• Keylogger: Software that collects keyboard data – possibly to collect passwords or important account information. Keyloggers can then send this information back to criminals allowing them to impersonate users and, for example, robbing their online banking accounts.
• Botnet: Programs used to control, update or trigger activity in previously infected systems.
• Backdoor: A way of getting undetected access to a computer system.
• Zombie: A computer being controlled by another user to perform some malicious online tasks.
• Spam: Unwanted email, instant messages or other form of electronic communication. Spam clogs email inboxes and the sheer volume of spam (as much as 95% of all email traffic) slows networks.
• Phishing: is when someone fraudulently tries to get hold of important information such as passwords and bank account details by pretending to be a trustworthy source. Phishers may send authentic-looking emails asking for the data or with links to a fake web site.
• Adware: Strictly speaking this isn’t a threat, but an annoyance. It refers to any software that bombards you with unwanted advertising.