Malware is malicious software that is created by fraudsters and criminals to infiltrate computers. It can take many forms and is used for a large number of illegal purposes such as stealing personal information, deleting or corrupting data, creating botnets (networks of infected computers) and bypassing security software. There are many forms of malware the most common types are Viruses, Worms, Trojans, Spyware and Scareware. 

What Is a Virus?

A computer virus attaches itself to a program or file enabling it to spread from one computer to another, leaving infections as it travels. Almost all viruses are attached to an executable file, which means the virus may exist on your computer but it actually cannot infect your computer unless you run or open the malicious program. Because a virus is spread by human action people will unknowingly continue the spread of a computer virus by sharing infecting files or sending emails with viruses as attachments in the email. 

What Is a Worm?

Worms spread from computer to computer, but unlike a virus, it has the capability to travel without any human action. A worm takes advantage of file or information transport features on your system, which is what allows it to travel unaided.

The biggest danger with a worm is its capability to replicate itself on your system, so rather than your computer sending out a single worm, it could send out hundreds or thousands of copies of itself, creating a huge devastating effect. One example would be for a worm to send a copy of itself to everyone listed in your e-mail address book. Then, the worm replicates and sends itself out to everyone listed in each of the receiver's address book, and the manifest continues on down the line.

Due to the copying nature of a worm and its capability to travel across networks the end result in most cases is that the worm consumes too much system memory, causing network servers and individual computers to stop responding.

What Is a Trojan horse?

A Trojan Horse, at first glance will appear to be useful software but will actually do damage once installed or run on your computer. Those on the receiving end of a Trojan Horse are usually tricked into opening them because they appear to be receiving legitimate software or files from a legitimate source. When a Trojan is activated on your computer, the results can vary. Some Trojans are designed to be more annoying than malicious (like changing your desktop, adding silly active desktop icons) or they can cause serious damage by deleting files and destroying information on your system. Trojans are also known to create a backdoor on your computer that gives malicious users access to your system, possibly allowing confidential or personal information to be compromised. Unlike viruses and worms, Trojans do not reproduce by infecting other files nor do they self-replicate. 

What is Spyware? 

Spyware is similar to a Trojan Horse in that users unwittingly install the product when they install something else. A common way to become a victim of spyware is to download certain peer to peer file swapping products that are available today. 

Spyware works like adware but is usually a separate program that is installed unknowingly when you install another freeware type program or application. Once installed, the spyware monitors user activity on the Internet and transmits that information in the background to someone else. Spyware can also gather information about email addresses and even passwords and credit card numbers.

What is Scareware? 

Scareware is rogue security software. It is designed specifically to damage or disrupt your computer system. In this case, not only is the software going to disrupt your system, it's going to try and trick you into making an insecure credit card purchase. 

Rogue anti-virus programs usually appears in the form of a fake Windows warning on your computer system that reads something like, you have a specific number of viruses on your computer (usually in the hundreds) and that this software has detected those viruses. To get rid of these viruses, you're prompted to buy the full-version of the antivirus software (which is really rogue antivirus software).

What is Ransomware? 

Ransomware is a form of malware in which software code effectively holds a user's computer hostage until a "ransom" fee is paid. Ransomware often infiltrates a PC as a computer worm or Trojan horse that takes advantage of open security vulnerabilities. Most ransomware attacks are the result of clicking on an infected e-mail attachment or visiting a hacked website. 

Upon compromising a computer, ransomware will typically either lock a user's system or encrypt files on the computer and then demand payment before the system or files will be restored

 Protection

Not keeping your software up to date can result in serious issues, affecting both your computer and your own personal security. These include:

• Viruses, spyware and other malware.
• Cyber-criminal attacks.
• Crashing, freezing and generally poor performance.

As well as resolving security issues, software updates frequently contain improvements and new features.

Software manufacturers release regular updates such as security updates or critical updates, which protect against malware and security exploits. Other types of updates correct errors that enhance the software’s functionality, and are not necessarily security related.

From time to time you will receive a notification from software manufacturers, in the form of an alert on your screen, that updates are available. You will normally be given the choice of whether to download and install the update immediately or later.

Some software updates require you to restart your computer in order to complete the installation process. Again, you will normally be given the option of doing this immediately or later.

These updates should be installed as soon as possible.

Several types of security software are necessary for basic online security. Security software essentials include firewall and antivirus programs.

A firewall is usually your computer's first line of defence, it controls who and what can communicate with your computer online. Allowing communications that it knows are safe and blocking unsafe traffic from ever reaching your computer.

The next line of defence is your antivirus software, which monitors all online activities and protects your computer from viruses, worms, Trojan horses, and other types of malicious programs. More recent versions of antivirus programs also protect from spyware and potentially unwanted programs such as adware. Having security software that gives you control over software you may not want and protects you from online threats is essential to staying safe on the Internet. Your antivirus and antispyware software should be configured to update itself, and it should do so every time you connect to the Internet.